A measurement of observables sensitive to effects of colour reconnection in top-quark pair-production events is presented using 139 fb$^{-1}$ of 13$\,$TeV proton-proton collision data collected by the ATLAS detector at the LHC. Events are selected by requiring exactly one isolated electron and one isolated muon with opposite charge and two or three jets, where exactly two jets are required to be $b$-tagged. For the selected events, measurements are presented for the charged-particle multiplicity, the scalar sum of the transverse momenta of the charged particles, and the same scalar sum in bins of charged-particle multiplicity. These observables are unfolded to the stable-particle level, thereby correcting for migration effects due to finite detector resolution, acceptance and efficiency effects. The particle-level measurements are compared with different colour reconnection models in Monte Carlo generators. These measurements disfavour some of the colour reconnection models and provide inputs to future optimisation of the parameters in Monte Carlo generators.
Binning used for the measured $\sum_{n_{\text{ch}}} p_{\text{T}}$ in bins of $n_\text{ch}$ observable.
Event yields obtained after the event selection. The expected event yields from $t\bar{t}$ production and the various background processes are compared with the observed event yield. The fractional contributions from $t\bar{t}$ production and the background processes to the expected event yield is given in %. The processes labelled by `Others' include production of $Z$+jets and diboson background events. The uncertainties include the MC statistical uncertainty and the normalisation uncertainty.
Summary of the estimated pile-up scale factors $c_{\text{PU}}$, parameterisd in $\mu$ and $n_{\text{trk,out}}$. All values have a statistical precision of 0.01.
Cross-section measurements of top-quark pair production where the hadronically decaying top quark has transverse momentum greater than $355$ GeV and the other top quark decays into $\ell \nu b$ are presented using 139 fb$^{-1}$ of data collected by the ATLAS experiment during proton-proton collisions at the LHC. The fiducial cross-section at $\sqrt{s}=13$ TeV is measured to be $\sigma = 1.267 \pm 0.005 \pm 0.053$ pb, where the uncertainties reflect the limited number of data events and the systematic uncertainties, giving a total uncertainty of $4.2\%$. The cross-section is measured differentially as a function of variables characterising the $t\bar{t}$ system and additional radiation in the events. The results are compared with various Monte Carlo generators, including comparisons where the generators are reweighted to match a parton-level calculation at next-to-next-to-leading order. The reweighting improves the agreement between data and theory. The measured distribution of the top-quark transverse momentum is used to set limits on the Wilson coefficients of the dimension-six operators $O_{tG}$ and $O_{tq}^{(8)}$ in the effective field theory framework.
- - - - - - - - Overview of HEPData Record - - - - - - - - <br/><br/> <b>Fiducial phase space definitions:</b><br/> <ul> <li> NLEP = 1, either E or MU, PT > 27 GeV, ABS ETA < 2.5 <li> NJETS >= 2, R = 0.4, PT > 26 GeV, ABS ETA < 2.5 <li> NBJETS >= 2 <li> NJETS >= 1, R=1, PT > 355 GeV, ABS ETA < 2.0, top-tagged </ul><br/> <u>1D:</u><br/> Spectra:<br/> <ul><br/> <li>SIG (<a href="1651136742?version=1&table=Table 1">Table 1</a> ) <li>DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 2">Table 2</a> ) <li>1/SIG*DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 4">Table 4</a> ) <li>DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 5">Table 5</a> ) <li>1/SIG*DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 7">Table 7</a> ) <li>DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 8">Table 8</a> ) <li>1/SIG*DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 10">Table 10</a> ) <li>DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 11">Table 11</a> ) <li>1/SIG*DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 13">Table 13</a> ) <li>DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 14">Table 14</a> ) <li>1/SIG*DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 16">Table 16</a> ) <li>DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 17">Table 17</a> ) <li>1/SIG*DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 19">Table 19</a> ) <li>DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 20">Table 20</a> ) <li>1/SIG*DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 22">Table 22</a> ) <li>DSIG/DDPHIOPI_THAD_BLEP (<a href="1651136742?version=1&table=Table 23">Table 23</a> ) <li>1/SIG*DSIG/DDPHIOPI_THAD_BLEP (<a href="1651136742?version=1&table=Table 25">Table 25</a> ) <li>DSIG/DPT_TTBAR (<a href="1651136742?version=1&table=Table 26">Table 26</a> ) <li>1/SIG*DSIG/DPT_TTBAR (<a href="1651136742?version=1&table=Table 28">Table 28</a> ) <li>DSIG/DDPHIOPI_TTBAR (<a href="1651136742?version=1&table=Table 29">Table 29</a> ) <li>1/SIG*DSIG/DDPHIOPI_TTBAR (<a href="1651136742?version=1&table=Table 31">Table 31</a> ) <li>DSIG/DHT (<a href="1651136742?version=1&table=Table 32">Table 32</a> ) <li>1/SIG*DSIG/DHT (<a href="1651136742?version=1&table=Table 34">Table 34</a> ) <li>DSIG/DNJETS (<a href="1651136742?version=1&table=Table 35">Table 35</a> ) <li>1/SIG*DSIG/DNJETS (<a href="1651136742?version=1&table=Table 37">Table 37</a> ) <li>DSIG/DPT_J1 (<a href="1651136742?version=1&table=Table 38">Table 38</a> ) <li>1/SIG*DSIG/DPT_J1 (<a href="1651136742?version=1&table=Table 40">Table 40</a> ) <li>DSIG/DM_J1_THAD (<a href="1651136742?version=1&table=Table 41">Table 41</a> ) <li>1/SIG*DSIG/DM_J1_THAD (<a href="1651136742?version=1&table=Table 43">Table 43</a> ) <li>DSIG/DDPHIOPI_THAD_J1 (<a href="1651136742?version=1&table=Table 44">Table 44</a> ) <li>1/SIG*DSIG/DDPHIOPI_THAD_J1 (<a href="1651136742?version=1&table=Table 46">Table 46</a> ) <li>DSIG/DDPHIOPI_THAD_J2 (<a href="1651136742?version=1&table=Table 47">Table 47</a> ) <li>1/SIG*DSIG/DDPHIOPI_THAD_J2 (<a href="1651136742?version=1&table=Table 49">Table 49</a> ) <li>DSIG/DDPHIOPI_J1_J2 (<a href="1651136742?version=1&table=Table 50">Table 50</a> ) <li>1/SIG*DSIG/DDPHIOPI_J1_J2 (<a href="1651136742?version=1&table=Table 52">Table 52</a> ) <li>DSIG/DPT_J2 (<a href="1651136742?version=1&table=Table 53">Table 53</a> ) <li>1/SIG*DSIG/DPT_J2 (<a href="1651136742?version=1&table=Table 55">Table 55</a> ) </ul><br/> Statistical covariance matrices: <ul> <li>DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 3">Table 3</a> ) <li>DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 6">Table 6</a> ) <li>DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 9">Table 9</a> ) <li>DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 12">Table 12</a> ) <li>DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 15">Table 15</a> ) <li>DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 18">Table 18</a> ) <li>DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 21">Table 21</a> ) <li>DSIG/DDPHIOPI_THAD_BLEP (<a href="1651136742?version=1&table=Table 24">Table 24</a> ) <li>DSIG/DPT_TTBAR (<a href="1651136742?version=1&table=Table 27">Table 27</a> ) <li>DSIG/DDPHIOPI_TTBAR (<a href="1651136742?version=1&table=Table 30">Table 30</a> ) <li>DSIG/DHT (<a href="1651136742?version=1&table=Table 33">Table 33</a> ) <li>DSIG/DNJETS (<a href="1651136742?version=1&table=Table 36">Table 36</a> ) <li>DSIG/DPT_J1 (<a href="1651136742?version=1&table=Table 39">Table 39</a> ) <li>DSIG/DM_J1_THAD (<a href="1651136742?version=1&table=Table 42">Table 42</a> ) <li>DSIG/DDPHIOPI_THAD_J1 (<a href="1651136742?version=1&table=Table 45">Table 45</a> ) <li>DSIG/DDPHIOPI_THAD_J2 (<a href="1651136742?version=1&table=Table 48">Table 48</a> ) <li>DSIG/DDPHIOPI_J1_J2 (<a href="1651136742?version=1&table=Table 51">Table 51</a> ) <li>DSIG/DPT_J2 (<a href="1651136742?version=1&table=Table 54">Table 54</a> ) </ul><br/> Inter-spectra statistical covariance matrices: <ul> <li>Statistical covariance between DSIG/DPT_THAD and DSIG/DSIG (<a href="1651136742?version=1&table=Table 104">Table 104</a> ) <li>Statistical covariance between DSIG/DPT_TLEP and DSIG/DSIG (<a href="1651136742?version=1&table=Table 105">Table 105</a> ) <li>Statistical covariance between DSIG/DPT_TLEP and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 106">Table 106</a> ) <li>Statistical covariance between DSIG/DM_TTBAR and DSIG/DSIG (<a href="1651136742?version=1&table=Table 107">Table 107</a> ) <li>Statistical covariance between DSIG/DM_TTBAR and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 108">Table 108</a> ) <li>Statistical covariance between DSIG/DM_TTBAR and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 109">Table 109</a> ) <li>Statistical covariance between DSIG/DABS_Y_THAD and DSIG/DSIG (<a href="1651136742?version=1&table=Table 110">Table 110</a> ) <li>Statistical covariance between DSIG/DABS_Y_THAD and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 111">Table 111</a> ) <li>Statistical covariance between DSIG/DABS_Y_THAD and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 112">Table 112</a> ) <li>Statistical covariance between DSIG/DABS_Y_THAD and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 113">Table 113</a> ) <li>Statistical covariance between DSIG/DABS_Y_TLEP and DSIG/DSIG (<a href="1651136742?version=1&table=Table 114">Table 114</a> ) <li>Statistical covariance between DSIG/DABS_Y_TLEP and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 115">Table 115</a> ) <li>Statistical covariance between DSIG/DABS_Y_TLEP and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 116">Table 116</a> ) <li>Statistical covariance between DSIG/DABS_Y_TLEP and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 117">Table 117</a> ) <li>Statistical covariance between DSIG/DABS_Y_TLEP and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 118">Table 118</a> ) <li>Statistical covariance between DSIG/DY_TTBAR and DSIG/DSIG (<a href="1651136742?version=1&table=Table 119">Table 119</a> ) <li>Statistical covariance between DSIG/DY_TTBAR and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 120">Table 120</a> ) <li>Statistical covariance between DSIG/DY_TTBAR and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 121">Table 121</a> ) <li>Statistical covariance between DSIG/DY_TTBAR and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 122">Table 122</a> ) <li>Statistical covariance between DSIG/DY_TTBAR and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 123">Table 123</a> ) <li>Statistical covariance between DSIG/DY_TTBAR and DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 124">Table 124</a> ) <li>Statistical covariance between DSIG/DHT_TTBAR and DSIG/DSIG (<a href="1651136742?version=1&table=Table 125">Table 125</a> ) <li>Statistical covariance between DSIG/DHT_TTBAR and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 126">Table 126</a> ) <li>Statistical covariance between DSIG/DHT_TTBAR and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 127">Table 127</a> ) <li>Statistical covariance between DSIG/DHT_TTBAR and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 128">Table 128</a> ) <li>Statistical covariance between DSIG/DHT_TTBAR and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 129">Table 129</a> ) <li>Statistical covariance between DSIG/DHT_TTBAR and DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 130">Table 130</a> ) <li>Statistical covariance between DSIG/DHT_TTBAR and DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 131">Table 131</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_BLEP and DSIG/DSIG (<a href="1651136742?version=1&table=Table 132">Table 132</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_BLEP and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 133">Table 133</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_BLEP and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 134">Table 134</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_BLEP and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 135">Table 135</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_BLEP and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 136">Table 136</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_BLEP and DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 137">Table 137</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_BLEP and DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 138">Table 138</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_BLEP and DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 139">Table 139</a> ) <li>Statistical covariance between DSIG/DPT_TTBAR and DSIG/DSIG (<a href="1651136742?version=1&table=Table 140">Table 140</a> ) <li>Statistical covariance between DSIG/DPT_TTBAR and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 141">Table 141</a> ) <li>Statistical covariance between DSIG/DPT_TTBAR and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 142">Table 142</a> ) <li>Statistical covariance between DSIG/DPT_TTBAR and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 143">Table 143</a> ) <li>Statistical covariance between DSIG/DPT_TTBAR and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 144">Table 144</a> ) <li>Statistical covariance between DSIG/DPT_TTBAR and DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 145">Table 145</a> ) <li>Statistical covariance between DSIG/DPT_TTBAR and DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 146">Table 146</a> ) <li>Statistical covariance between DSIG/DPT_TTBAR and DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 147">Table 147</a> ) <li>Statistical covariance between DSIG/DPT_TTBAR and DSIG/DDPHIOPI_THAD_BLEP (<a href="1651136742?version=1&table=Table 148">Table 148</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_TTBAR and DSIG/DSIG (<a href="1651136742?version=1&table=Table 149">Table 149</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_TTBAR and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 150">Table 150</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_TTBAR and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 151">Table 151</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_TTBAR and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 152">Table 152</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_TTBAR and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 153">Table 153</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_TTBAR and DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 154">Table 154</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_TTBAR and DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 155">Table 155</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_TTBAR and DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 156">Table 156</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_TTBAR and DSIG/DDPHIOPI_THAD_BLEP (<a href="1651136742?version=1&table=Table 157">Table 157</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_TTBAR and DSIG/DPT_TTBAR (<a href="1651136742?version=1&table=Table 158">Table 158</a> ) <li>Statistical covariance between DSIG/DHT and DSIG/DSIG (<a href="1651136742?version=1&table=Table 159">Table 159</a> ) <li>Statistical covariance between DSIG/DHT and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 160">Table 160</a> ) <li>Statistical covariance between DSIG/DHT and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 161">Table 161</a> ) <li>Statistical covariance between DSIG/DHT and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 162">Table 162</a> ) <li>Statistical covariance between DSIG/DHT and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 163">Table 163</a> ) <li>Statistical covariance between DSIG/DHT and DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 164">Table 164</a> ) <li>Statistical covariance between DSIG/DHT and DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 165">Table 165</a> ) <li>Statistical covariance between DSIG/DHT and DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 166">Table 166</a> ) <li>Statistical covariance between DSIG/DHT and DSIG/DDPHIOPI_THAD_BLEP (<a href="1651136742?version=1&table=Table 167">Table 167</a> ) <li>Statistical covariance between DSIG/DHT and DSIG/DPT_TTBAR (<a href="1651136742?version=1&table=Table 168">Table 168</a> ) <li>Statistical covariance between DSIG/DHT and DSIG/DDPHIOPI_TTBAR (<a href="1651136742?version=1&table=Table 169">Table 169</a> ) <li>Statistical covariance between DSIG/DNJETS and DSIG/DSIG (<a href="1651136742?version=1&table=Table 170">Table 170</a> ) <li>Statistical covariance between DSIG/DNJETS and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 171">Table 171</a> ) <li>Statistical covariance between DSIG/DNJETS and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 172">Table 172</a> ) <li>Statistical covariance between DSIG/DNJETS and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 173">Table 173</a> ) <li>Statistical covariance between DSIG/DNJETS and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 174">Table 174</a> ) <li>Statistical covariance between DSIG/DNJETS and DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 175">Table 175</a> ) <li>Statistical covariance between DSIG/DNJETS and DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 176">Table 176</a> ) <li>Statistical covariance between DSIG/DNJETS and DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 177">Table 177</a> ) <li>Statistical covariance between DSIG/DNJETS and DSIG/DDPHIOPI_THAD_BLEP (<a href="1651136742?version=1&table=Table 178">Table 178</a> ) <li>Statistical covariance between DSIG/DNJETS and DSIG/DPT_TTBAR (<a href="1651136742?version=1&table=Table 179">Table 179</a> ) <li>Statistical covariance between DSIG/DNJETS and DSIG/DDPHIOPI_TTBAR (<a href="1651136742?version=1&table=Table 180">Table 180</a> ) <li>Statistical covariance between DSIG/DNJETS and DSIG/DHT (<a href="1651136742?version=1&table=Table 181">Table 181</a> ) <li>Statistical covariance between DSIG/DPT_J1 and DSIG/DSIG (<a href="1651136742?version=1&table=Table 182">Table 182</a> ) <li>Statistical covariance between DSIG/DPT_J1 and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 183">Table 183</a> ) <li>Statistical covariance between DSIG/DPT_J1 and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 184">Table 184</a> ) <li>Statistical covariance between DSIG/DPT_J1 and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 185">Table 185</a> ) <li>Statistical covariance between DSIG/DPT_J1 and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 186">Table 186</a> ) <li>Statistical covariance between DSIG/DPT_J1 and DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 187">Table 187</a> ) <li>Statistical covariance between DSIG/DPT_J1 and DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 188">Table 188</a> ) <li>Statistical covariance between DSIG/DPT_J1 and DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 189">Table 189</a> ) <li>Statistical covariance between DSIG/DPT_J1 and DSIG/DDPHIOPI_THAD_BLEP (<a href="1651136742?version=1&table=Table 190">Table 190</a> ) <li>Statistical covariance between DSIG/DPT_J1 and DSIG/DPT_TTBAR (<a href="1651136742?version=1&table=Table 191">Table 191</a> ) <li>Statistical covariance between DSIG/DPT_J1 and DSIG/DDPHIOPI_TTBAR (<a href="1651136742?version=1&table=Table 192">Table 192</a> ) <li>Statistical covariance between DSIG/DPT_J1 and DSIG/DHT (<a href="1651136742?version=1&table=Table 193">Table 193</a> ) <li>Statistical covariance between DSIG/DPT_J1 and DSIG/DNJETS (<a href="1651136742?version=1&table=Table 194">Table 194</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DSIG (<a href="1651136742?version=1&table=Table 195">Table 195</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 196">Table 196</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 197">Table 197</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 198">Table 198</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 199">Table 199</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 200">Table 200</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 201">Table 201</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 202">Table 202</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DDPHIOPI_THAD_BLEP (<a href="1651136742?version=1&table=Table 203">Table 203</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DPT_TTBAR (<a href="1651136742?version=1&table=Table 204">Table 204</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DDPHIOPI_TTBAR (<a href="1651136742?version=1&table=Table 205">Table 205</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DHT (<a href="1651136742?version=1&table=Table 206">Table 206</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DNJETS (<a href="1651136742?version=1&table=Table 207">Table 207</a> ) <li>Statistical covariance between DSIG/DM_J1_THAD and DSIG/DPT_J1 (<a href="1651136742?version=1&table=Table 208">Table 208</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DSIG (<a href="1651136742?version=1&table=Table 209">Table 209</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 210">Table 210</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 211">Table 211</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 212">Table 212</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 213">Table 213</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 214">Table 214</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 215">Table 215</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 216">Table 216</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DDPHIOPI_THAD_BLEP (<a href="1651136742?version=1&table=Table 217">Table 217</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DPT_TTBAR (<a href="1651136742?version=1&table=Table 218">Table 218</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DDPHIOPI_TTBAR (<a href="1651136742?version=1&table=Table 219">Table 219</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DHT (<a href="1651136742?version=1&table=Table 220">Table 220</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DNJETS (<a href="1651136742?version=1&table=Table 221">Table 221</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DPT_J1 (<a href="1651136742?version=1&table=Table 222">Table 222</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J1 and DSIG/DM_J1_THAD (<a href="1651136742?version=1&table=Table 223">Table 223</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DSIG (<a href="1651136742?version=1&table=Table 224">Table 224</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 225">Table 225</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 226">Table 226</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 227">Table 227</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 228">Table 228</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 229">Table 229</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 230">Table 230</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 231">Table 231</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DDPHIOPI_THAD_BLEP (<a href="1651136742?version=1&table=Table 232">Table 232</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DPT_TTBAR (<a href="1651136742?version=1&table=Table 233">Table 233</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DDPHIOPI_TTBAR (<a href="1651136742?version=1&table=Table 234">Table 234</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DHT (<a href="1651136742?version=1&table=Table 235">Table 235</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DNJETS (<a href="1651136742?version=1&table=Table 236">Table 236</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DPT_J1 (<a href="1651136742?version=1&table=Table 237">Table 237</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DM_J1_THAD (<a href="1651136742?version=1&table=Table 238">Table 238</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_THAD_J2 and DSIG/DDPHIOPI_THAD_J1 (<a href="1651136742?version=1&table=Table 239">Table 239</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DSIG (<a href="1651136742?version=1&table=Table 240">Table 240</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 241">Table 241</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 242">Table 242</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 243">Table 243</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 244">Table 244</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 245">Table 245</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 246">Table 246</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 247">Table 247</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DDPHIOPI_THAD_BLEP (<a href="1651136742?version=1&table=Table 248">Table 248</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DPT_TTBAR (<a href="1651136742?version=1&table=Table 249">Table 249</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DDPHIOPI_TTBAR (<a href="1651136742?version=1&table=Table 250">Table 250</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DHT (<a href="1651136742?version=1&table=Table 251">Table 251</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DNJETS (<a href="1651136742?version=1&table=Table 252">Table 252</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DPT_J1 (<a href="1651136742?version=1&table=Table 253">Table 253</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DM_J1_THAD (<a href="1651136742?version=1&table=Table 254">Table 254</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DDPHIOPI_THAD_J1 (<a href="1651136742?version=1&table=Table 255">Table 255</a> ) <li>Statistical covariance between DSIG/DDPHIOPI_J1_J2 and DSIG/DDPHIOPI_THAD_J2 (<a href="1651136742?version=1&table=Table 256">Table 256</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DSIG (<a href="1651136742?version=1&table=Table 257">Table 257</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DPT_THAD (<a href="1651136742?version=1&table=Table 258">Table 258</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DPT_TLEP (<a href="1651136742?version=1&table=Table 259">Table 259</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DM_TTBAR (<a href="1651136742?version=1&table=Table 260">Table 260</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DABS_Y_THAD (<a href="1651136742?version=1&table=Table 261">Table 261</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DABS_Y_TLEP (<a href="1651136742?version=1&table=Table 262">Table 262</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DY_TTBAR (<a href="1651136742?version=1&table=Table 263">Table 263</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DHT_TTBAR (<a href="1651136742?version=1&table=Table 264">Table 264</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DDPHIOPI_THAD_BLEP (<a href="1651136742?version=1&table=Table 265">Table 265</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DPT_TTBAR (<a href="1651136742?version=1&table=Table 266">Table 266</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DDPHIOPI_TTBAR (<a href="1651136742?version=1&table=Table 267">Table 267</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DHT (<a href="1651136742?version=1&table=Table 268">Table 268</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DNJETS (<a href="1651136742?version=1&table=Table 269">Table 269</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DPT_J1 (<a href="1651136742?version=1&table=Table 270">Table 270</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DM_J1_THAD (<a href="1651136742?version=1&table=Table 271">Table 271</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DDPHIOPI_THAD_J1 (<a href="1651136742?version=1&table=Table 272">Table 272</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DDPHIOPI_THAD_J2 (<a href="1651136742?version=1&table=Table 273">Table 273</a> ) <li>Statistical covariance between DSIG/DPT_J2 and DSIG/DDPHIOPI_J1_J2 (<a href="1651136742?version=1&table=Table 274">Table 274</a> ) </ul><br/> <u>2D:</u><br/> Spectra: <ul> <li>1/SIG*D2SIG/DPT_J1/DNJETS (NJETS = 1) (<a href="1651136742?version=1&table=Table 56">Table 56</a> ) <li>1/SIG*D2SIG/DPT_J1/DNJETS (NJETS = 2) (<a href="1651136742?version=1&table=Table 57">Table 57</a> ) <li>1/SIG*D2SIG/DPT_J1/DNJETS (NJETS $\geq$ 3) (<a href="1651136742?version=1&table=Table 58">Table 58</a> ) <li>D2SIG/DPT_J1/DNJETS (NJETS = 1) (<a href="1651136742?version=1&table=Table 59">Table 59</a> ) <li>D2SIG/DPT_J1/DNJETS (NJETS = 2) (<a href="1651136742?version=1&table=Table 60">Table 60</a> ) <li>D2SIG/DPT_J1/DNJETS (NJETS $\geq$ 3) (<a href="1651136742?version=1&table=Table 61">Table 61</a> ) <li>1/SIG*D2SIG/DPT_J1/DPT_THAD ( 355.0 GeV < PT_THAD < 398.0 GeV) (<a href="1651136742?version=1&table=Table 68">Table 68</a> ) <li>1/SIG*D2SIG/DPT_J1/DPT_THAD ( 398.0 GeV < PT_THAD < 496.0 GeV) (<a href="1651136742?version=1&table=Table 69">Table 69</a> ) <li>1/SIG*D2SIG/DPT_J1/DPT_THAD ( 496.0 GeV < PT_THAD < 2000.0 GeV) (<a href="1651136742?version=1&table=Table 70">Table 70</a> ) <li>D2SIG/DPT_J1/DPT_THAD ( 355.0 GeV < PT_THAD < 398.0 GeV) (<a href="1651136742?version=1&table=Table 71">Table 71</a> ) <li>D2SIG/DPT_J1/DPT_THAD ( 398.0 GeV < PT_THAD < 496.0 GeV) (<a href="1651136742?version=1&table=Table 72">Table 72</a> ) <li>D2SIG/DPT_J1/DPT_THAD ( 496.0 GeV < PT_THAD < 2000.0 GeV) (<a href="1651136742?version=1&table=Table 73">Table 73</a> ) <li>1/SIG*D2SIG/DDPHIOPI_THAD_J1/DPT_THAD ( 355.0 GeV < PT_THAD < 398.0 GeV) (<a href="1651136742?version=1&table=Table 80">Table 80</a> ) <li>1/SIG*D2SIG/DDPHIOPI_THAD_J1/DPT_THAD ( 398.0 GeV < PT_THAD < 496.0 GeV) (<a href="1651136742?version=1&table=Table 81">Table 81</a> ) <li>1/SIG*D2SIG/DDPHIOPI_THAD_J1/DPT_THAD ( 496.0 GeV < PT_THAD < 2000.0 GeV) (<a href="1651136742?version=1&table=Table 82">Table 82</a> ) <li>D2SIG/DDPHIOPI_THAD_J1/DPT_THAD ( 355.0 GeV < PT_THAD < 398.0 GeV) (<a href="1651136742?version=1&table=Table 83">Table 83</a> ) <li>D2SIG/DDPHIOPI_THAD_J1/DPT_THAD ( 398.0 GeV < PT_THAD < 496.0 GeV) (<a href="1651136742?version=1&table=Table 84">Table 84</a> ) <li>D2SIG/DDPHIOPI_THAD_J1/DPT_THAD ( 496.0 GeV < PT_THAD < 2000.0 GeV) (<a href="1651136742?version=1&table=Table 85">Table 85</a> ) <li>1/SIG*D2SIG/DDPHIOPI_THAD_J1/DNJETS (NJETS = 1) (<a href="1651136742?version=1&table=Table 92">Table 92</a> ) <li>1/SIG*D2SIG/DDPHIOPI_THAD_J1/DNJETS (NJETS = 2) (<a href="1651136742?version=1&table=Table 93">Table 93</a> ) <li>1/SIG*D2SIG/DDPHIOPI_THAD_J1/DNJETS (NJETS $\geq$ 3) (<a href="1651136742?version=1&table=Table 94">Table 94</a> ) <li>D2SIG/DDPHIOPI_THAD_J1/DNJETS (NJETS = 1) (<a href="1651136742?version=1&table=Table 95">Table 95</a> ) <li>D2SIG/DDPHIOPI_THAD_J1/DNJETS (NJETS = 2) (<a href="1651136742?version=1&table=Table 96">Table 96</a> ) <li>D2SIG/DDPHIOPI_THAD_J1/DNJETS (NJETS $\geq$ 3) (<a href="1651136742?version=1&table=Table 97">Table 97</a> ) </ul><br/> Statistical covariance matrices: <ul> <li>Statistical covariance matrix for D2SIG/DPT_J1/DNJETS between the 1st and 1st bins of NJETS (<a href="1651136742?version=1&table=Table 62">Table 62</a> ) <li>Statistical covariance matrix for D2SIG/DPT_J1/DNJETS between the 2nd and 1st bins of NJETS (<a href="1651136742?version=1&table=Table 63">Table 63</a> ) <li>Statistical covariance matrix for D2SIG/DPT_J1/DNJETS between the 2nd and 2nd bins of NJETS (<a href="1651136742?version=1&table=Table 64">Table 64</a> ) <li>Statistical covariance matrix for D2SIG/DPT_J1/DNJETS between the 3rd and 1st bins of NJETS (<a href="1651136742?version=1&table=Table 65">Table 65</a> ) <li>Statistical covariance matrix for D2SIG/DPT_J1/DNJETS between the 3rd and 2nd bins of NJETS (<a href="1651136742?version=1&table=Table 66">Table 66</a> ) <li>Statistical covariance matrix for D2SIG/DPT_J1/DNJETS between the 3rd and 3rd bins of NJETS (<a href="1651136742?version=1&table=Table 67">Table 67</a> ) <li>Statistical covariance matrix for D2SIG/DPT_J1/DPT_THAD between the 1st and 1st bins of PT_THAD (<a href="1651136742?version=1&table=Table 74">Table 74</a> ) <li>Statistical covariance matrix for D2SIG/DPT_J1/DPT_THAD between the 2nd and 1st bins of PT_THAD (<a href="1651136742?version=1&table=Table 75">Table 75</a> ) <li>Statistical covariance matrix for D2SIG/DPT_J1/DPT_THAD between the 2nd and 2nd bins of PT_THAD (<a href="1651136742?version=1&table=Table 76">Table 76</a> ) <li>Statistical covariance matrix for D2SIG/DPT_J1/DPT_THAD between the 3rd and 1st bins of PT_THAD (<a href="1651136742?version=1&table=Table 77">Table 77</a> ) <li>Statistical covariance matrix for D2SIG/DPT_J1/DPT_THAD between the 3rd and 2nd bins of PT_THAD (<a href="1651136742?version=1&table=Table 78">Table 78</a> ) <li>Statistical covariance matrix for D2SIG/DPT_J1/DPT_THAD between the 3rd and 3rd bins of PT_THAD (<a href="1651136742?version=1&table=Table 79">Table 79</a> ) <li>Statistical covariance matrix for D2SIG/DDPHIOPI_THAD_J1/DPT_THAD between the 1st and 1st bins of PT_THAD (<a href="1651136742?version=1&table=Table 86">Table 86</a> ) <li>Statistical covariance matrix for D2SIG/DDPHIOPI_THAD_J1/DPT_THAD between the 2nd and 1st bins of PT_THAD (<a href="1651136742?version=1&table=Table 87">Table 87</a> ) <li>Statistical covariance matrix for D2SIG/DDPHIOPI_THAD_J1/DPT_THAD between the 2nd and 2nd bins of PT_THAD (<a href="1651136742?version=1&table=Table 88">Table 88</a> ) <li>Statistical covariance matrix for D2SIG/DDPHIOPI_THAD_J1/DPT_THAD between the 3rd and 1st bins of PT_THAD (<a href="1651136742?version=1&table=Table 89">Table 89</a> ) <li>Statistical covariance matrix for D2SIG/DDPHIOPI_THAD_J1/DPT_THAD between the 3rd and 2nd bins of PT_THAD (<a href="1651136742?version=1&table=Table 90">Table 90</a> ) <li>Statistical covariance matrix for D2SIG/DDPHIOPI_THAD_J1/DPT_THAD between the 3rd and 3rd bins of PT_THAD (<a href="1651136742?version=1&table=Table 91">Table 91</a> ) <li>Statistical covariance matrix for D2SIG/DDPHIOPI_THAD_J1/DNJETS between the 1st and 1st bins of NJETS (<a href="1651136742?version=1&table=Table 98">Table 98</a> ) <li>Statistical covariance matrix for D2SIG/DDPHIOPI_THAD_J1/DNJETS between the 2nd and 1st bins of NJETS (<a href="1651136742?version=1&table=Table 99">Table 99</a> ) <li>Statistical covariance matrix for D2SIG/DDPHIOPI_THAD_J1/DNJETS between the 2nd and 2nd bins of NJETS (<a href="1651136742?version=1&table=Table 100">Table 100</a> ) <li>Statistical covariance matrix for D2SIG/DDPHIOPI_THAD_J1/DNJETS between the 3rd and 1st bins of NJETS (<a href="1651136742?version=1&table=Table 101">Table 101</a> ) <li>Statistical covariance matrix for D2SIG/DDPHIOPI_THAD_J1/DNJETS between the 3rd and 2nd bins of NJETS (<a href="1651136742?version=1&table=Table 102">Table 102</a> ) <li>Statistical covariance matrix for D2SIG/DDPHIOPI_THAD_J1/DNJETS between the 3rd and 3rd bins of NJETS (<a href="1651136742?version=1&table=Table 103">Table 103</a> ) </ul><br/>
Total cross-section at particle level in the boosted topology. Note that the values shown here are obtained by propagating the individual uncertainties to the measured cross-sections, while the covariance matrices are evaluated using pseudo-experiments as described in the text. The measured cross-section is compared with the prediction obtained with the Powheg+Pythia8 Monte Carlo generator.
Absolute differential cross-section as a function of $p_T^{t,h}$ at particle level in the boosted topology. The measured differential cross-section is compared with the prediction obtained with the Powheg+Pythia8 Monte Carlo generator.
The production cross section of a top quark pair in association with a photon is measured in proton-proton collisions in the decay channel with two oppositely charged leptons (e$^\pm\mu^\mp$, e$^+$e$^-$, or $\mu^+\mu^-$). The measurement is performed using 138 fb$^{-1}$ of proton-proton collision data recorded by the CMS experiment at $\sqrt{s} =$ 13 TeV during the 2016-2018 data-taking period of the CERN LHC. A fiducial phase space is defined such that photons radiated by initial-state particles, top quarks, or any of their decay products are included. An inclusive cross section of 175.2 $\pm$ 2.5 (stat) $\pm$ 6.3 (syst) fb is measured in a signal region with at least one jet coming from the hadronization of a bottom quark and exactly one photon with transverse momentum above 20 GeV. Differential cross sections are measured as functions of several kinematic observables of the photon, leptons, and jets, and compared to standard model predictions. The measurements are also interpreted in the standard model effective field theory framework, and limits are found on the relevant Wilson coefficients from these results alone and in combination with a previous CMS measurement of the $\mathrm{t\bar{t}}\gamma$ production process using the lepton+jets final state.
Observed and predicted event yields as a function of $p_{T}(\gamma)$ in the $e\mu$ channel, after the fit to the data.
Observed and predicted event yields as a function of $p_{T}(\gamma)$ in the $ee$ channel, after the fit to the data.
Observed and predicted event yields as a function of $p_{T}(\gamma)$ in the $\mu\mu$ channel, after the fit to the data.
The production cross section of a top quark pair in association with a photon is measured in proton-proton collisions at a center-of-mass energy of 13 TeV. The data set, corresponding to an integrated luminosity of 137 fb$^{-1}$, was recorded by the CMS experiment during the 2016-2018 data taking of the LHC. The measurements are performed in a fiducial volume defined at the particle level. Events with an isolated, highly energetic lepton, at least three jets from the hadronization of quarks, among which at least one is b tagged, and one isolated photon are selected. The inclusive fiducial $\mathrm{t\overline{t}}\gamma$ cross section, for a photon with transverse momentum greater than 20 GeV and pseudorapidity $\lvert \eta\rvert$$\lt$ 1.4442, is measured to be 798 $\pm$ 7 (stat) $\pm$ 48 (syst) fb, in good agreement with the prediction from the standard model at next-to-leading order in quantum chromodynamics. The differential cross sections are also measured as a function of several kinematic observables and interpreted in the framework of the standard model effective field theory (EFT), leading to the most stringent direct limits to date on anomalous electromagnetic dipole moment interactions of the top quark and the photon.
Distribution of $p_{T}(\gamma)$ in the $N_{jet}\geq 3$ signal region.
Distribution of $p_{T}(\gamma)$ in the $N_{jet}\geq 3$ signal region.
Distribution of $m_{T}(W)$ in the $N_{jet}\geq 3$ signal region.
The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric ($\hat{d}_\mathrm{t}$) and chromomagnetic ($\hat{\mu}_\mathrm{t}$) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb$^{-1}$. The linearized variable $A_\mathrm{FB}^{(1)}$ is used to approximate the asymmetry. Candidate $\mathrm{t\bar{t}}$ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for $\mathrm{t\bar{t}}$ final states. The values found for the parameters are $A_\mathrm{FB}^{(1)} =$ 0.048 $^{+0.095}_{-0.087}$ (stat) $^{+0.020}_{-0.029}$ (syst), $\hat{\mu}_\mathrm{t} =-$ 0.024 $^{+0.013}_{-0.009}$ (stat) $^{+0.016}_{-0.011}$ (syst), and a limit is placed on the magnitude of $|\hat{d}_\mathrm{t}|$ $<$ 0.03 at 95% confidence level.
Linearized top quark forward-backward production asymmetry $A_{FB}^{(1)}$
Top quark anomalous chromomagnetic dipole moment $\hat{\mu}_{t}$
Top quark anomalous chromoelectric dipole moment $\hat{d}_{t}$
The cross section of top quark pair production is measured in the $\mathrm{t\bar{t}}\to (\ell\nu_{\ell})(\tau_\mathrm{h}\nu_{\tau})\mathrm{b\bar{b}}$ final state, where $\tau_\mathrm{h}$ refers to the hadronic decays of the $\tau$ lepton, and $\ell$ is either an electron or a muon. The data sample corresponds to an integrated luminosity of 35.9 fb$^{-1}$ collected in proton-proton collisions at $\sqrt{s}=$ 13 TeV with the CMS detector. The measured cross section is $\sigma_{\mathrm{t\bar{t}}} =$ 781 $\pm$ 7 (stat) $\pm$ 62 (syst) $\pm$ 20 (lum) pb, and the ratio of the partial width $\Gamma($t$\to\tau\nu_{\tau}$b) to the total decay width of the top quark is measured to be 0.1050 $\pm$ 0.0009 (stat) $\pm$ 0.0071 (syst). This is the first measurement of the $\mathrm{t\bar{t}}$ production cross section in proton-proton collisions at $\sqrt{s}=$ 13 TeV that explicitly includes $\tau$ leptons. The ratio of the cross sections in the $\ell\tau_\mathrm{h}$ and $\ell\ell$ final states yields a value $R_{\ell\tau_\mathrm{h}/\ell\ell}=$ 0.973 $\pm$ 0.009 (stat) $\pm$ 0.066 (syst), consistent with lepton universality.
The measured inclusive top quark pair production cross section in the dilepton final state with one tau lepton.
The ratio between top quark production cross sections measured in lepton-tau and light dilepton final states.
The ratio of the partial width to the total decay width of the top quark.
Measurements of the top quark polarization and top quark pair ($\mathrm{t\bar{t}}$) spin correlations are presented using events containing two oppositely charged leptons (e$^+$e$^-$, e$^\pm\mu^\mp$, or $\mu^+\mu^-$) produced in proton-proton collisions at a center-of-mass energy of 13 TeV. The data were recorded by the CMS experiment at the LHC in 2016 and correspond to an integrated luminosity of 35.9 fb$^{-1}$. A set of parton-level normalized differential cross sections, sensitive to each of the independent coefficients of the spin-dependent parts of the $\mathrm{t\bar{t}}$ production density matrix, is measured for the first time at 13 TeV. The measured distributions and extracted coefficients are compared with standard model predictions from simulations at next-to-leading-order (NLO) accuracy in quantum chromodynamics (QCD), and from NLO QCD calculations including electroweak corrections. All measurements are found to be consistent with the expectations of the standard model. The normalized differential cross sections are used in fits to constrain the anomalous chromomagnetic and chromoelectric dipole moments of the top quark to $-$0.24 $<C_\text{tG}/\Lambda^{2}$ $<$ 0.07 TeV$^{-2}$ and $-$0.33 $< C^{I}_\text{tG}/\Lambda^{2}$ $<$ 0.20 TeV$^{-2}$, respectively, at 95% confidence level.
Figure 4, normalized differential cross section for $\cos\theta_{1}^{k}$
Figure 4, normalized differential cross section for $\cos\theta_{2}^{k}$
Figure 4, normalized differential cross section for $\cos\theta_{1}^{r}$
A top quark mass measurement is performed using 35.9 fb$^{-1}$ of LHC proton-proton collision data collected with the CMS detector at $\sqrt{s} =$ 13 TeV. The measurement uses the $\mathrm{t\overline{t}}$ all-jets final state. A kinematic fit is performed to reconstruct the decay of the $\mathrm{t\overline{t}}$ system and suppress the multijet background. Using the ideogram method, the top quark mass ($m_\mathrm{t}$) is determined, simultaneously constraining an additional jet energy scale factor (JSF). The resulting value of $m_\mathrm{t}$ = 172.34 $\pm$ 0.20 (stat+JSF) $\pm$ 0.70 (syst) GeV is in good agreement with previous measurements. In addition, a combined measurement that uses the $\mathrm{t\overline{t}}$ lepton+jets and all-jets final states is presented, using the same mass extraction method, and provides an $m_\mathrm{t}$ measurement of 172.26 $\pm$ 0.07 (stat+JSF) $\pm$ 0.61 (syst) GeV. This is the first combined $m_\mathrm{t}$ extraction from the lepton+jets and all-jets channels through a single likelihood function.
Measured top quark mass $m_{t}$
Measurements of differential top quark pair $\mathrm{t\overline{t}}$ cross sections using events produced in proton-proton collisions at a centre-of-mass energy of 13 TeV containing two oppositely charged leptons are presented. The data were recorded by the CMS experiment at the CERN LHC in 2016 and correspond to an integrated luminosity of 35.9 fb$^{-1}$. The differential cross sections are presented as functions of kinematic observables of the top quarks and their decay products, the $\mathrm{t\overline{t}}$ system, and the total number of jets in the event. The differential cross sections are defined both with particle-level objects in a fiducial phase space close to that of the detector acceptance and with parton-level top quarks in the full phase space. All results are compared with standard model predictions from Monte Carlo simulations with next-to-leading-order (NLO) accuracy in quantum chromodynamics (QCD) at matrix-element level interfaced to parton-shower simulations. Where possible, parton-level results are compared to calculations with beyond-NLO precision in QCD. Significant disagreement is observed between data and all predictions for several observables. The measurements are used to constrain the top quark chromomagnetic dipole moment in an effective field theory framework at NLO in QCD and to extract $\mathrm{t\overline{t}}$ and leptonic charge asymmetries.
Measured absolute differential cross section at parton level as a function of $p_{T}^{t}$.
Covariance matrix of the absolute differential cross section at parton level as a function of $p_{T}^{t}$.
Measured normalised differential cross section at parton level as a function of $p_{T}^{t}$.
A measurement of jet substructure observables is presented using \ttbar events in the lepton+jets channel from proton-proton collisions at $\sqrt{s}=$ 13 TeV recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. Multiple jet substructure observables are measured for jets identified as bottom, light-quark, and gluon jets, as well as for inclusive jets (no flavor information). The results are unfolded to the particle level and compared to next-to-leading-order predictions from POWHEG interfaced with the parton shower generators PYTHIA 8 and HERWIG 7, as well as from SHERPA 2 and DIRE2. A value of the strong coupling at the Z boson mass, $\alpha_S(m_\mathrm{Z}) = $ 0.115$^{+0.015}_{-0.013}$, is extracted from the substructure data at leading-order plus leading-log accuracy.
Distribution of $\lambda_{0}^{0}$ (N) reconstructed from charged particles with pt > 1 GeV, unfolded to the particle level.
Distribution of $\lambda_{0}^{0}$ (N) reconstructed from charged particles with pt > 1 GeV, unfolded to the particle level.
Distribution of $\lambda_{0}^{2}$ ($p_{T}^{d,*})$ reconstructed from charged particles with pt > 1 GeV, unfolded to the particle level.
The mass of the top quark is measured using a sample of $\mathrm{t\overline{t}}$ events collected by the CMS detector using proton-proton collisions at $\sqrt{s} =$ 13 TeV at the CERN LHC. Events are selected with one isolated muon or electron and at least four jets from data corresponding to an integrated luminosity of 35.9 fb$^{-1}$. For each event the mass is reconstructed from a kinematic fit of the decay products to a $\mathrm{t\overline{t}}$ hypothesis. Using the ideogram method, the top quark mass is determined simultaneously with an overall jet energy scale factor (JSF), constrained by the mass of the W boson in $\mathrm{q\overline{q}'}$ decays. The measurement is calibrated on samples simulated at next-to-leading order matched to a leading-order parton shower. The top quark mass is found to be 172.25 $\pm$ 0.08 (stat+JSF) $\pm$ 0.62 (syst) GeV. The dependence of this result on the kinematic properties of the event is studied and compared to predictions of different models of $\mathrm{t\overline{t}}$ production, and no indications of a bias in the measurements are observed.
Measured top quark mass $m_{t}$
Normalized differential cross sections for top quark pair production are measured in the dilepton (e$^+$e$^-$, $\mu^+\mu^-$, and $\mu^\mp$e$^\pm$) decay channels in proton-proton collisions at a center-of-mass energy of 13 TeV. The measurements are performed with data corresponding to an integrated luminosity of 2.1 fb$^{-1}$ using the CMS detector at the LHC. The cross sections are measured differentially as a function of the kinematic properties of the leptons, jets from bottom quark hadronization, top quarks, and top quark pairs at the particle and parton levels. The results are compared to several Monte Carlo generators that implement calculations up to next-to-leading order in perturbative quantum chromodynamics interfaced with parton showering, and also to fixed-order theoretical calculations of top quark pair production up to next-to-next-to-leading order.
Normalized differential ttbar cross sections with statistical and systematic uncertainties at the particle level as a function of pt(lepton).
Normalized differential ttbar cross sections with statistical and systematic uncertainties at the particle level as a function of pt(jet).
Normalized differential ttbar cross sections with statistical and systematic uncertainties at the particle level as a function of pt(top).
Normalized double-differential cross sections for top quark pair (t t-bar) production are measured in pp collisions at a centre-of-mass energy of 8 TeV with the CMS experiment at the LHC. The analyzed data correspond to an integrated luminosity of 19.7 inverse femtobarns. The measurement is performed in the dilepton e+/- mu-/+ final state. The t t-bar cross section is determined as a function of various pairs of observables characterizing the kinematics of the top quark and t t-bar system. The data are compared to calculations using perturbative quantum chromodynamics at next-to-leading and approximate next-to-next-to-leading orders. They are also compared to predictions of Monte Carlo event generators that complement fixed-order computations with parton showers, hadronization, and multiple-parton interactions. Overall agreement is observed with the predictions, which is improved when the latest global sets of proton parton distribution functions are used. The inclusion of the measured t t-bar cross sections in a fit of parametrized parton distribution functions is shown to have significant impact on the gluon distribution.
The measured normalized $t\bar{t}$ double-differential cross sections in different bins of $y(t)$ and $p_{T}(t)$, along with their relative statistical and systematic uncertainties expressed as percentages.
The correlation matrix of statistical uncertainties for the normalized $t\bar{t}$ double-differential cross sections as a function of $y(t)$ and $p_{T}(t)$. The values are expressed as percentages. For bin indices see Table 5.
Sources and values of the relative systematic uncertainties in percent of the measured normalized $t\bar{t}$ double-differential cross sections as a function of $y(t)$ and $p_{T}(t)$. For bin indices see Table 5.
Ratios of top-quark pair to $Z$-boson cross sections measured from proton--proton collisions at the LHC centre-of-mass energies of $\sqrt s=13$TeV, 8TeV, and 7TeV are presented by the ATLAS Collaboration. Single ratios, at a given $\sqrt s$ for the two processes and at different $\sqrt s$ for each process, as well as double ratios of the two processes at different $\sqrt s$, are evaluated. The ratios are constructed using previously published ATLAS measurements of the $t\overline{t}$ and $Z$-boson production cross sections, corrected to a common phase space where required, and a new analysis of $Z \rightarrow \ell^+ \ell^-$ where $\ell=e,\mu$ at $\sqrt s=13$TeV performed with data collected in 2015 with an integrated luminosity of $3.2$fb$^{-1}$. Correlations of systematic uncertainties are taken into account when evaluating the uncertainties in the ratios. The correlation model is also used to evaluate the combined cross section of the $Z\rightarrow e^+e^-$ and the $Z\rightarrow \mu^+ \mu^-$ channels for each $\sqrt s$ value. The results are compared to calculations performed at next-to-next-to-leading-order accuracy using recent sets of parton distribution functions. The data demonstrate significant power to constrain the gluon distribution function for the Bjorken-$x$ values near 0.1 and the light-quark sea for $x<0.02$.
Measured fiducial cross section times leptonic branching ratio for Z/gamma* production in the Z/gamma* -> e+e- final state at 13TeV.
Measured fiducial cross section times leptonic branching ratio for Z/gamma* production in the Z/gamma* -> mu+ mu- final state at 13TeV.
Breakdown of systematic uncertainties in percent for the measured fiducial cross section times leptonic branching ratio for Z/gamma* production in the Z/gamma* -> e+e- final state at 13TeV.
The cross section of top quark-antiquark pair production in proton-proton collisions at sqrt(s) = 13 TeV is measured by the CMS experiment at the LHC, using data corresponding to an integrated luminosity of 2.2 inverse femtobarns. The measurement is performed by analyzing events in which the final state includes one electron, one muon, and two or more jets, at least one of which is identified as originating from hadronization of a b quark. The measured cross section is 815 +/- 9 (stat) +/- 38 (syst) +/- 19 (lumi) pb, in agreement with the expectation from the standard model.
Summary of the individual contributions to the uncertainty in the $\sigma_{t\bar{t}}$ measurement.
Measurement of the $t\bar{t}$ production cross-section in $pp$ collisions at $\sqrt{s} = 13$ TeV.
Number of dilepton events obtained after applying the full selection. The results are given for the individual sources of background, $t\bar{t}$ signal with a top quark mass of 172.5 GeV and $\sigma_{t\bar{t}}$ = 832 +/- 46 pb, and data. The uncertainties correspond to statistical and systematic components.
Differential and double-differential cross sections for the production of top quark pairs in proton-proton collisions at 13 TeV are measured as a function of jet multiplicity and of kinematic variables of the top quarks and the top quark-antiquark system. This analysis is based on data collected by the CMS experiment at the LHC corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurements are performed in the lepton+jets decay channels with a single muon or electron in the final state. The differential cross sections are presented at particle level, within a phase space close to the experimental acceptance, and at parton level in the full phase space. The results are compared to several standard model predictions.
Absolute cross section at particle level.
Covariance matrix of absolute cross section at particle level.
Absolute cross section at particle level.
A first measurement of the top quark mass using the decay channel t to (W to l nu) (b to J/psi + X to mu+ mu- + X) is presented. The analysis uses events selected from the proton-proton collisions recorded with the CMS detector at the LHC at a center-of-mass energy of 8 TeV. The data correspond to an integrated luminosity of 19.7 inverse femtobarns, with 666 t t-bar and single top quark candidate events containing a reconstructed J/psi candidate decaying into an oppositely-charged muon pair. The mass of the (J/psi + l) system, where l is an electron or a muon from W boson decay, is used to extract a top quark mass of 173.5 +/- 3.0 (stat) +/- 0.9 (syst) GeV.
Number of selected events from simulations and observed in data. The uncertainties are statistical.
Summary of the impact of systematic uncertainties on the top quark mass according to the contributions from each source.
Measurements of normalized differential cross-sections of top quark pair ($t\bar t$) production are presented as a function of the mass, the transverse momentum and the rapidity of the $t\bar t$ system in proton-proton collisions at center-of-mass energies of $\sqrt{s}$ = 7 TeV and 8 TeV. The dataset corresponds to an integrated luminosity of 4.6 fb$^{-1}$ at 7 TeV and 20.2 fb$^{-1}$ at 8 TeV, recorded with the ATLAS detector at the Large Hadron Collider. Events with top quark pair signatures are selected in the dilepton final state, requiring exactly two charged leptons and at least two jets with at least one of the jets identified as likely to contain a $b$-hadron. The measured distributions are corrected for detector effects and selection efficiency to cross-sections at the parton level. The differential cross-sections are compared with different Monte Carlo generators and theoretical calculations of $t\bar t$ production. The results are consistent with the majority of predictions in a wide kinematic range.
Parton-level normalized $t\bar t$ differential cross-sections for $t\bar t$ system mass $m_{t\bar t}$ at $\sqrt{s}$ = 7 TeV. The cross-sections in the last bins include events (if any) beyond of the bin edges. The uncertainties quoted in the second column represent the statistical and systematic uncertainties added in quadrature.
Parton-level normalized $t\bar t$ differential cross-sections for the $t\bar t$ system transverse momentum $p_{T, t\bar t}$ at $\sqrt{s}$ = 7 TeV. The cross-sections in the last bins include events (if any) beyond of the bin edges. The uncertainties quoted in the second column represent the statistical and systematic uncertainties added in quadrature.
Parton-level normalized $t\bar t$ differential cross-sections for the $t\bar t$ system absolute rapidity $|y_{t\bar t}|$ at $\sqrt{s}$ = 7 TeV. The cross-sections in the last bins include events (if any) beyond of the bin edges. The uncertainties quoted in the second column represent the statistical and systematic uncertainties added in quadrature.
Measurements are reported of the normalized differential cross sections for top quark pair production with respect to four kinematic event variables: the missing transverse energy; the scalar sum of the jet transverse momentum (pT); the scalar sum of the pT of all objects in the event; and the pT of leptonically decaying W bosons from top quark decays. The data sample, collected using the CMS detector at the LHC, consists of 5.0 inverse femtobarns of proton-proton collisions at sqrt(s) = 7 TeV and 19.7 inverse femtobarns at sqrt(s) = 8 TeV. Top quark pair events containing one electron or muon are selected. The results are presented after correcting for detector effects to allow direct comparison with theoretical predictions. No significant deviations from the predictions of several standard model event simulation generators are observed.
Normalized $t\bar{t}$ differential cross section measurements with respect to the $E^{miss}_{T}$ variable at a center-of-mass energy of 7 TeV (combination of electron and muon channels).
Normalized $t\bar{t}$ differential cross section measurements with respect to the $H_T$ variable at a center-of-mass energy of 7 TeV (combination of electron and muon channels).
Normalized $t\bar{t}$ differential cross section measurements with respect to the $S_T$ variable at a center-of-mass energy of 7 TeV (combination of electron and muon channels).
This paper describes a measurement of the inclusive top quark pair production cross-section ($\sigma_{t\bar{t}}$) with a data sample of 3.2 fb$^{-1}$ of proton--proton collisions at a centre-of-mass energy of $\sqrt{s}$=13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron--muon pair in the final state. Jets containing $b$-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two $b$-tagged jets are counted and used to determine simultaneously $\sigma_{t\bar{t}}$ and the efficiency to reconstruct and $b$-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: $\sigma_{t\bar{t}}$= 818 $\pm$ 8 (stat) $\pm$ 27 (syst) $\pm$ 19 (lumi) $\pm$ 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented.
Measured cross-section for $t\bar{t}$ events using $e\mu$ events with b-tagged jets in pp collisions at $\sqrt{s}$=13 TeV.
Measured fiducial cross-section for $t\bar{t}$ events producing an $e\mu$ pair, each lepton originating directly from t $\rightarrow$ W $\rightarrow$ l or via a leptonic $\tau$ decay t $\rightarrow$ W $\rightarrow$ $\tau$ $\rightarrow$ l and satisfying p$_{\mathrm{T}} > $ 25 GeV and $|\eta| <$ 2.5.
The W boson helicity fractions from top quark decays in t t-bar events are measured using data from proton-proton collisions at a centre-of-mass energy of 8 TeV. The data were collected in 2012 with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.8 inverse femtobarns. Events are reconstructed with either one muon or one electron, along with four jets in the final state, with two of the jets being identified as originating from b quarks. The measured helicity fractions from both channels are combined, yielding F[0] = 0.681 +/- 0.012 (stat) +/- 0.023 (syst), F[L] = 0.323 +/- 0.008 (stat) +/- 0.014 (syst), and F[R] = -0.004 +/- 0.005 (stat) +/- 0.014 (syst) for the longitudinal, left-, and right-handed components of the helicity, respectively. These measurements of the W boson helicity fractions are the most accurate to date and they agree with the predictions from the standard model.
Measurement of the W longitudinal (F0), left- (FL) and righ- (FR) components of the boson helicity fractions from electron+jets final states in top quark pair decays. The helicity fractions F0 and FL are measured simultaneously and are strongly anti-correlated, with statistical correlation coefficient -0.950.
Measurement of the W longitudinal (F0), left- (FL) and righ- (FR) components of the boson helicity fractions from muon+jets final states in top quark pair decays. The helicity fractions F0 and FL are measured simultaneously and are strongly anti-correlated, with statistical correlation coefficient -0.957.
Measurement of the W longitudinal (F0), left- (FL) and righ- (FR) components of the boson helicity fractions from lepton+jets final states in top quark pair decays. The helicity fractions F0 and FL are measured simultaneously and are strongly anti-correlated, with statistical correlation coefficient -0.959, and total correlation, considering both statistical and systematic uncertainties, of -0.87.
The cross section for pair production of top quarks (t-tbar) with high transverse momenta is measured in pp collisions, collected with the CMS detector at the LHC with sqrt(s) = 8 TeV in data corresponding to an integrated luminosity of 19.7 inverse femtobarns. The measurement is performed using lepton+jets events, where one top quark decays semileptonically, while the second top quark decays to a hadronic final state. The hadronic decay is reconstructed as a single, large-radius jet, and identified as a top quark candidate using jet substructure techniques. The integrated cross section and the differential cross sections as a function of top quark pt and rapidity are measured at particle level within a fiducial region related to the detector-level requirements and at parton level. The particle-level integrated cross section is found to be sigma[t-tbar] = 0.499 +/- 0.035 (stat+syst) +/- 0.095 (theory) +/- 0.013 (lumi) pb for top quark pt > 400 GeV. The parton-level measurement is sigma[t-tbar] = 1.44 +/- 0.10 (stat+syst) +/- 0.29 (theory) +/- 0.04 (lumi) pb. The integrated and differential cross section results are compared to predictions from several event generators.
The measurements of the integrated cross sections for $p_T^t > 400$ GeV.
Differential $t\bar{t}$ cross section in bins of $p_T$ for the $t$ jet at the particle level and the top quark at parton level.
Differential $t\bar{t}$ cross section in bins of $y$ for the $t$ jet at the particle level and the top quark at parton level.
A novel technique for measuring the mass of the top quark that uses only the kinematic properties of its charged decay products is presented. Top quark pair events with final states with one or two charged leptons and hadronic jets are selected from the data set of 8 TeV proton-proton collisions, corresponding to an integrated luminosity of 19.7 inverse femtobarns. By reconstructing secondary vertices inside the selected jets and computing the invariant mass of the system formed by the secondary vertex and an isolated lepton, an observable is constructed that is sensitive to the top quark mass that is expected to be robust against the energy scale of hadronic jets. The main theoretical systematic uncertainties, concerning the modeling of the fragmentation and hadronization of b quarks and the reconstruction of secondary vertices from the decays of b hadrons, are studied. A top quark mass of 173.68 +/- 0.20 (stat) +1.58 -0.97 (syst) GeV is measured. The overall systematic uncertainty is dominated by the uncertainty in the b quark fragmentation and the modeling of kinematic properties of the top quark.
Combined measurement of the top quark mass.
Number of observed events and expected purity of top quark production ($t\bar{t}$ and single top quarks) for the five channels investigated in this analysis.
Summary of the systematic uncertainties in the final measurement. In cases where there are two variations of one source of uncertainty, the first and second numbers correspond, respectively, to the down and up variations. The total uncertainties are taken as the separate quadratic sum of all positive and negative shifts. For the contributions marked with a (*), the shift of the single variation including its sign is given, but the uncertainty is counted symmetrically in both up and down directions for the total uncertainty calculation.
The charge asymmetry in t t-bar events is measured using dilepton final states produced in pp collisions at the LHC at sqrt(s) = 8 TeV. The data sample, collected with the CMS detector, corresponds to an integrated luminosity of 19.5 inverse femtobarns. The measurements are performed using events with two oppositely charged leptons (electrons or muons) and two or more jets, where at least one of the jets is identified as originating from a bottom quark. The charge asymmetry is measured from differences in kinematic distributions, unfolded to the parton level, of positively and negatively charged top quarks and leptons. The t t-bar and leptonic charge asymmetries are found to be 0.011 +/- 0.011 (stat) +/- 0.007 (syst) and 0.003 +/- 0.006 (stat) +/- 0.003 (syst), respectively. These results, as well as charge asymmetry measurements made as a function of the invariant mass, rapidity, and transverse momentum of the t t-bar system, are in agreement with predictions of the standard model.
Inclusive values of the asymmetry variables.
Values of the 6 bins of the normalized differential cross section as a function of $\Delta|y_\mathrm{t}|$.
Statistical covariance matrix for the 6 bins of the normalized differential cross section as a function of $\Delta|y_\mathrm{t}|$.
The inclusive cross section for top quark pair production is measured in proton-proton collisions at sqrt(s) = 7 and 8 TeV, corresponding to 5.0 and 19.7 invers-femtobarns, respectively, with the CMS experiment at the LHC. The cross sections are measured in the electron-muon channel using a binned likelihood fit to multi-differential final state distributions related to identified b quark jets and other jets in the event. The measured cross section values are 173.6 +/- 2.1 (stat) +4.5-4.0 (syst) +/- 3.8 (lumi) pb at sqrt(s) = 7 TeV, and 244.9 +/- 1.4 (stat) +6.3-5.5 (syst) +/- 6.4 (lumi) pb at sqrt(s) = 8 TeV, in good agreement with QCD calculations at next-to-next-to-leading-order accuracy. The ratio of the cross sections measured at 7 and 8 TeV is determined, as well as cross sections in the fiducial regions defined by the acceptance requirements on the two charged leptons in the final state. The cross section results are used to determine the top quark pole mass via the dependence of the theoretically predicted cross section on the mass, giving a best result of 173.8 +1.7-1.8 GeV. The data at sqrt(s) = 8 TeV are also used to set limits, for two neutralino mass values, on the pair production of supersymmetric top squarks with masses close to the top quark mass.
Measurement of the visible $t\bar{t}$ production cross-section in $pp$ collisions at $\sqrt{s} = 7$ and $8$ TeV. The visible cross section is defined for events containing an oppositely charged $\rm{e}\mu$ pair from the decay chain ${\rm t} \rightarrow {\rm W b} \rightarrow {\ell} \nu {\rm b}$ (including ${\rm W} \rightarrow \tau \nu \rightarrow {\ell} \nu \nu \nu$) and with both leptons satisfying $p_T > 20\, \rm{GeV}$ and $|{\eta}| < 2.4$.
Measurement of the inclusive $t\bar{t}$ production cross-section in $pp$ collisions at $\sqrt{s} = 7$ and $8$ TeV.
Top quark pole mass at NNLO+NNLL extracted by comparing the measured $t\bar{t}$ production cross sections at 7 and 8 TeV with predictions employing different PDF sets. The uncertainties of the CT14 PDF set are scaled to 68% confidence level.
Measurements of the top quark-antiquark (t t-bar) spin correlations and the top quark polarization are presented for t t-bar pairs produced in pp collisions at sqrt(s) = 8 TeV. The data correspond to an integrated luminosity of 19.5 inverse femtobarns collected with the CMS detector at the LHC. The measurements are performed using events with two oppositely charged leptons (electrons or muons) and two or more jets, where at least one of the jets is identified as originating from a bottom quark. The spin correlations and polarization are measured from the angular distributions of the two selected leptons, both inclusively and differentially, with respect to the invariant mass, rapidity, and transverse momentum of the t t-bar system. The measurements are unfolded to the parton level and found to be in agreement with predictions of the standard model. A search for new physics in the form of anomalous top quark chromo moments is performed. No evidence of new physics is observed, and exclusion limits on the real part of the chromo-magnetic dipole moment and the imaginary part of the chromo-electric dipole moment are evaluated.
Inclusive values of the asymmetry variables.
Values of the 12 bins of the normalized differential cross section as a function of $\left|\Delta \phi_{\ell^+\ell^-}\right|$.
Statistical covariance matrix for the 12 bins of the normalized differential cross section as a function of $\left|\Delta \phi_{\ell^+\ell^-}\right|$.
In the $pp \rightarrow t\bar{t}$ process the angular distributions of top and anti-top quarks are expected to present a subtle difference, which could be enhanced by processes not included in the Standard Model. This Letter presents a measurement of the charge asymmetry in events where the top-quark pair is produced with a large invariant mass. The analysis is performed on 20.3 fb$^{-1}$ of $pp$ collision data at $\sqrt{s} =$ 8 TeV collected by the ATLAS experiment at the LHC, using reconstruction techniques specifically designed for the decay topology of highly boosted top quarks. The charge asymmetry in a fiducial region with large invariant mass of the top-quark pair ($m_{t\bar{t}} > $ 0.75 TeV) and an absolute rapidity difference of the top and anti-top quark candidates within $-$2 $ < |y_t| - |y_{\bar{t}}| <$ 2 is measured to be 4.2 $\pm$ 3.2%, in agreement with the Standard Model prediction at next-to-leading order. A differential measurement in three $t\bar{t}$ mass bins is also presented.
The measured charge asymmetry after the unfolding to parton level in four intervals of the invariant mass of the $t\bar{t}$ system. The phase space is limited to $|(\Delta |y|)|<$ 2. The uncertainties correspond to the sum in quadrature of statistical and systematic uncertainties (for the data) or to the theory uncertainty (for the SM prediction).
The consistency of the spin correlation strength in top quark pair production with the standard model (SM) prediction is tested in the muon + jets final state. The events are selected from pp collisions, collected by the CMS detector, at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 inverse femtobarns. The data are compared with the expectation for the spin correlation predicted by the SM and with the expectation of no correlation. Using a template fit method, the fraction of events that show SM spin correlations is measured to be 0.72 +/- 0.08 (stat) +0.15 -0.13 (syst), representing the most precise measurement of this quantity in the lepton + jets final state to date.
The result of the template fit of distributions for uncorrelated and SM-like correlated ttbar spins.
Measurements of normalized differential cross-sections of top-quark pair production are presented as a function of the top-quark, $t\bar{t}$ system and event-level kinematic observables in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=8$ TeV}. The observables have been chosen to emphasize the $t\bar{t}$ production process and to be sensitive to effects of initial- and final-state radiation, to the different parton distribution functions, and to non-resonant processes and higher-order corrections. The dataset corresponds to an integrated luminosity of 20.3 fb$^{-1}$, recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider. Events are selected in the lepton+jets channel, requiring exactly one charged lepton and at least four jets with at least two of the jets tagged as originating from a $b$-quark. The measured spectra are corrected for detector effects and are compared to several Monte Carlo simulations. The results are in fair agreement with the predictions over a wide kinematic range. Nevertheless, most generators predict a harder top-quark transverse momentum distribution at high values than what is observed in the data. Predictions beyond NLO accuracy improve the agreement with data at high top-quark transverse momenta. Using the current settings and parton distribution functions, the rapidity distributions are not well modelled by any generator under consideration. However, the level of agreement is improved when more recent sets of parton distribution functions are used.
Fiducial phase-space absolute differential cross-sections after combining the e+jets and $\mu$+jets channels for the $t\bar{t}$ system invariant mass $m^{t\bar{t}}$. All uncertainties are quoted as a percentage with respect to the cross-section values in each bin.
Fiducial phase-space relative differential cross-sections after combining the e+jets and $\mu$+jets channels for the $t\bar{t}$ system invariant mass $m^{t\bar{t}}$. All uncertainties are quoted as a percentage with respect to the cross-section values in each bin.
Fiducial phase-space absolute differential cross-sections after combining the e+jets and $\mu$+jets channels for the $t\bar{t}$ system transverse momentum $p_{T}^{t\bar{t}}$. All uncertainties are quoted as a percentage with respect to the cross-section values in each bin.
A measurement of the correlations between the polar angles of leptons from the decay of pair-produced $t$ and $\bar{t}$ quarks in the helicity basis is reported, using proton-proton collision data collected by the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 4.6fb$^{-1}$ at a center-of-mass energy of $\sqrt{s}=7$TeV collected during 2011. Candidate events are selected in the dilepton topology with large missing transverse momentum and at least two jets. The angles $\theta_1$ and $\theta_2$ between the charged leptons and the direction of motion of the parent quarks in the $t\bar{t}$ rest frame are sensitive to the spin information, and the distribution of {\mbox{$\cos\theta_1\cdot\cos\theta_2$}} is sensitive to the spin correlation between the $t$ and $\bar{t}$ quarks. The distribution is unfolded to parton level and compared to the next-to-leading order prediction. A good agreement is observed.
The numerical summary of the unfolded $\cos\theta_1\cdot\cos\theta_2$ distribution, with statistical and systematic uncertainties.
The correlation factors for the statistical uncertainties between any two bins of the unfolded distribution.
The top quark pair production cross section is measured for the first time in proton-proton collisions at sqrt(s) = 13 TeV by the CMS experiment at the CERN LHC, using data corresponding to an integrated luminosity of 43 inverse picobarns. The measurement is performed by analyzing events with at least one electron and one muon of opposite charge, and at least two jets. The measured cross section is 746 +/- 58 (stat) +/- 53 (syst) +/- 36 (lumi) pb, in agreement with the expectation from the standard model.
The first measurement of the $t\bar{t}$ production cross-section in $pp$ collisions at $\sqrt{s} = 13$ TeV.
The differential cross-section for pair production of top quarks with high transverse momentum is measured in 20.3 fb$^{-1}$ of proton-proton collisions at a center-of-mass energy of 8 TeV. The measurement is performed for $t\bar{t}$ events in the lepton+jets channel. The cross-section is reported as a function of the hadronically decaying top quark transverse momentum for values above 300 GeV. The hadronically decaying top quark is reconstructed as an anti-$k_t$ jet with radius parameter $R=1.0$ and identified with jet substructure techniques. The observed yield is corrected for detector effects to obtain a cross-section at particle level in a fiducial region close to the event selection. A parton-level cross-section extrapolated to the full phase space is also reported for top quarks with transverse momentum above 300 GeV. The predictions of a majority of next-to-leading-order and leading-order matrix-element Monte Carlo generators are found to agree with the measured cross-sections.
Fiducial particle-level differential cross-section, with statistical and systematic uncertainties, as a function of the top-jet candidate p_T.
Parton-level differential cross-section, with statistical and systematic uncertainties, as a function of the hadronically decaying top quark p_T.
The individual systematic uncertainties calculated as a percentage of the particle-level differential cross-section $d\sigma_{tt} / d p_{T,ptcl}$ in each bin. Variations on the two sides ("UP" and "DOWN") are separately quoted with their respective signs. Uncertainties smaller than 0.1% are neglected.
Jet multiplicity distributions in top quark pair (t t-bar) events are measured in pp collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC using a data set corresponding to an integrated luminosity of 19.7 inverse femtobarns. The measurement is performed in the dilepton decay channels (e+ e-, mu+ mu-, and e+/- mu-/+). The absolute and normalized differential cross sections for t t-bar production are measured as a function of the jet multiplicity in the event for different jet transverse momentum thresholds and the kinematic properties of the leading additional jets. The differential t t-bar b and t t-bar b b-bar cross sections are presented for the first time as a function of the kinematic properties of the leading additional b jets. Furthermore, the fraction of events without additional jets above a threshold is measured as a function of the transverse momenta of the leading additional jets and the scalar sum of the transverse momenta of all additional jets. The data are compared and found to be consistent with predictions from several perturbative quantum chromodynamics event generators and a next-to-leading order calculation.
Absolute differential ttbar cross sections as a function of the jet multiplicity for jets with pt > 30GeV, along with their statistical and systematic uncertainties. The results are presented at the particle level in the visible phase space of the ttbar decay products and the additional jets.
Normalized differential ttbar cross sections as a function of the jet multiplicity for jets with pt > 30GeV, along with their statistical and systematic uncertainties. The results are presented at the particle level in the visible phase space of the ttbar decay products and the additional jets.
Absolute differential ttbar cross sections as a function of the jet multiplicity for jets with pt > 60GeV, along with their statistical and systematic uncertainties. The results are presented at the particle level in the visible phase space of the ttbar decay products and the additional jets.
A new set of measurements of the top quark mass are presented, based on the proton-proton data recorded by the CMS experiment at the LHC at sqrt(s) = 8 TeV corresponding to a luminosity of 19.7 inverse femtobarns. The top quark mass is measured using the lepton + jets, all-jets and dilepton decay channels, giving values of 172.35 +/- 0.16 (stat) +/- 0.48 (syst) GeV, 172.32 +/- 0.25 (stat) +/- 0.59 (syst) GeV, and 172.82 +/- 0.19 (stat) +/- 1.22 (syst) GeV, respectively. When combined with the published CMS results at sqrt(s) = 7 TeV, they provide a top quark mass measurement of 172.44 +/- 0.13 (stat) +/- 0.47 (syst) GeV. The top quark mass is also studied as a function of the event kinematical properties in the lepton + jets decay channel. No indications of a kinematic bias are observed and the collision data are consistent with a range of predictions from current theoretical models of t t-bar production.
Measurement of $m_{t}$ as a function of the transverse momentum of the hadronically decaying top quark.
Measurement of $m_{t}$ as a function of the invariant mass of the tt¯ system.
Measurement of $m_{t}$ as a function of the transverse momentum of the tt¯ system.
This paper reports inclusive and differential measurements of the $t\bar{t}$ charge asymmetry $A_{\textrm{C}}$ in 20.3 fb$^{-1}$ of $\sqrt{s} = 8$ TeV $pp$ collisions recorded by the ATLAS experiment at the Large Hadron Collider at CERN. Three differential measurements are performed as a function of the invariant mass, transverse momentum and longitudinal boost of the $t\bar{t}$ system. The $t\bar{t}$ pairs are selected in the single-lepton channels ($e$ or $\mu$) with at least four jets, and a likelihood fit is used to reconstruct the $t\bar{t}$ event kinematics. A Bayesian unfolding procedure is performed to infer the asymmetry at parton level from the observed data distribution. The inclusive $t\bar{t}$ charge asymmetry is measured to be $A_{\textrm{C}} = 0.009 \pm 0.005$ (stat.$+$syst.). The inclusive and differential measurements are compatible with the values predicted by the Standard Model.
The inclusive $t\bar{t}$ production charge asymmetry, $A_C$, with statistical and systematic uncertainties combined.
Measured charge asymmetry, $A_C$, values for the electron and muon channels combined after unfolding as a function of the $t\bar{t}$ invariant mass, $m_{t\bar{t}}$. The quoted uncertainties include statistical and systematic components after the marginalisation.
Measured charge asymmetry, $A_C$, values for the electron and muon channels combined after unfolding as a function of the $t\bar{t}$ velocity along the z-axis, $\beta_{z,t\bar{t}}$. The quoted uncertainties include statistical and systematic components after the marginalisation.
The charge asymmetry in the production of top quark and antiquark pairs is measured in proton-proton collisions at a center-of-mass energy of 8 TeV. The data, corresponding to an integrated luminosity of 19.6 inverse femtobarns, were collected by the CMS experiment at the LHC. Events with a single isolated electron or muon, and four or more jets, at least one of which is likely to have originated from hadronization of a bottom quark, are selected. A template technique is used to measure the asymmetry in the distribution of differences in the top quark and antiquark absolute rapidities. The measured asymmetry is A[c,y] = [0.33 +/- 0.26 (stat) +/- 0.33 (syst)]%, which is the most precise result to date. The results are compared to calculations based on the standard model and on several beyond-the-standard-model scenarios.
The measured $t\bar{t}$ production asymmetry $A_c^y$.
The t t-bar charge asymmetry is measured in proton-proton collisions at a centre-of-mass energy of 8 TeV. The data, collected with the CMS experiment at the LHC, correspond to an integrated luminosity of 19.7 inverse femtobarns. Selected events contain an electron or a muon and four or more jets, where at least one jet is identified as originating from b-quark hadronization. The inclusive charge asymmetry is found to be 0.0010 +/- 0.0068 (stat) +/- 0.0037 (syst). In addition, differential charge asymmetries as a function of rapidity, transverse momentum, and invariant mass of the t t-bar system are studied. For the first time at the LHC, the measurements are also performed in a reduced fiducial phase space of top quark pair production, with an integrated result of -0.0035 +/- 0.0072 (stat) +/- 0.0031 (syst). All measurements are consistent within two standard deviations with zero asymmetry as well as with the predictions of the standard model.
Corrected asymmetry as a function of $|y_\mathrm{t\bar{t}}|$ in the fiducial phase space. The value 9999 is used as a placeholder for infinity. The correlation matrix for these values can be found in a separate table.
Correlation matrix for the asymmetries as a function of $|y_\mathrm{t\bar{t}}|$ in the fiducial phase space. Both statistical and systematic effects are considered.
Corrected asymmetry as a function of $p_\text{T}^\mathrm{t\bar{t}}$ in the fiducial phase space. The value 9999 is used as a placeholder for infinity. The correlation matrix for these values can be found in a separate table.
The distribution and orientation of energy inside jets is predicted to be an experimental handle on colour connections between the hard--scatter quarks and gluons initiating the jets. This Letter presents a measurement of the distribution of one such variable, the jet pull angle. The pull angle is measured for jets produced in $t\bar{t}$ events with one $W$ boson decaying leptonically and the other decaying to jets using 20.3 fb$^{-1}$ of data recorded with the ATLAS detector at a centre-of-mass energy of $\sqrt{s}=8$ TeV at the LHC. The jet pull angle distribution is corrected for detector resolution and acceptance effects and is compared to various models.
Normalised fiducial ttbar differential cross-section for the jet pull angle distribution constructed using all particles.
Normalised fiducial ttbar differential cross-section for the jet pull angle distribution constructed using charged particles.
Statistical bin-bin correlation matrix.
A search for new particles that decay into top quark pairs is reported. The search is performed with the ATLAS experiment at the LHC using an integrated luminosity of 20.3 fb$^{-1}$ of proton-proton collision data collected at a centre-of-mass energy of $\sqrt{s}=8$ TeV. The lepton-plus-jets final state is used, where the top pair decays to $W^+bW^-\bar{b}$, with one $W$ boson decaying leptonically and the other hadronically. The invariant mass spectrum of top quark pairs is examined for local excesses or deficits that are inconsistent with the Standard Model predictions. No evidence for a top quark pair resonance is found, and 95% confidence-level limits on the production rate are determined for massive states in benchmark models. The upper limits on the cross-section times branching ratio of a narrow $Z'$ boson decaying to top pairs range from 4.2 pb to 0.03 pb for resonance masses from 0.4 TeV to 3.0 TeV. A narrow leptophobic topcolour $Z'$ boson with mass below 1.8 TeV is excluded. Upper limits are set on the cross-section times branching ratio for a broad colour-octet resonance with $\Gamma/m =$ 15% decaying to $t\bar{t}$. These range from 2.5 pb to 0.03 pb for masses from 0.4 TeV to 3.0 TeV. A Kaluza-Klein excitation of the gluon in a Randall-Sundrum model is excluded for masses below 2.2 TeV.
Selection efficiency x Acceptance for a Z' resonance.
Selection efficiency x Acceptance for a KK gluon resonance.
Selection efficiency x Acceptance for a KK graviton resonance.
The normalized differential cross section for top quark pair (tt-bar) production is measured in pp collisions at a centre-of-mass energy of 8 TeV at the CERN LHC using the CMS detector in data corresponding to an integrated luminosity of 19.7 inverse femtobarns. The measurements are performed in the lepton + jets (e/mu + jets) and in the dilepton (e+e-, mu+mu-, and e+-mu-+) decay channels. The tt-bar cross section is measured as a function of the kinematic properties of the charged leptons, the jets associated to b quarks, the top quarks, and the tt-bar system. The data are compared with several predictions from perturbative quantum chromodynamics up to approximate next-to-next-to-leading-order precision. No significant deviations are observed relative to the standard model predictions.
Normalized differential tt cross section (from l+jets channel) as a function of the transverse momentum pt of the lepton. The results are presented at particle level in the fiducial phase space. The statistical and systematic uncertainties are added in quadrature to yield the total uncertainty.
Normalized differential tt cross section (from l+jets channel) as a function of the pseudo-rapidity of the lepton. The results are presented at particle level in the fiducial phase space. The statistical and systematic uncertainties are added in quadrature to yield the total uncertainty.
Normalized differential tt cross section (from l+jets channel) as a function of the transverse momentum pt(b-jet) of the b-jet. The results are presented at particle level in the fiducial phase space. The statistical and systematic uncertainties are added in quadrature to yield the total uncertainty.
Various differential cross-sections are measured in top-quark pair ($t\bar{t}$) events produced in proton-proton collisions at a centre-of-mass energy of $\sqrt{s} = 7$ TeV at the LHC with the ATLAS detector. These differential cross-sections are presented in a data set corresponding to an integrated luminosity of $4.6$ fb$^{-1}$. The differential cross-sections are presented in terms of kinematic variables, such as momentum, rapidity and invariant mass, of a top-quark proxyreferred to as the pseudo-top-quark as well as the pseudo-top-quark pair system. The dependence of the measurement on theoretical models is minimal. The measurements are performed on $t\bar{t}$ events in the lepton+jets channel, requiring exactly one charged lepton and at least four jets with at least two of them tagged as originating from a $b$-quark. The hadronic and leptonic pseudo-top-quarks are defined via the leptonic or hadronic decay mode of the $W$ boson produced by the top-quark decay in events with a single charged lepton. Differential cross-section measurements of the pseudo-top-quark variables are compared with several Monte Carlo models that implement next-to-leading order or leading-order multi-leg matrix-element calculations.
Measured $t\bar{t}$ differential cross-section and relative uncertainty as a function of the hadronic pseudo-top-quark $p_{\mathrm{T}}(\hat{t}_{\mathrm{h}})$in the muon channel. The results shown in this table are one of the inputs for the combined results.
Measured $t\bar{t}$ differential cross-section and relative uncertainty as a function of the hadronic pseudo-top-quark $p_{\mathrm{T}}(\hat{t}_{\mathrm{h}})$ in the electron channel. The results shown in this table are one of the inputs for the combined results.
Measured $t\bar{t}$ differential cross-section and relative uncertainty as a function of the hadronic pseudo-top-quark $|y(\hat{t}_{\mathrm{h}})|$ in the muon channel. The results shown in this table are one of the inputs for the combined results.
The $t\bar{t}$ production cross-section dependence on jet multiplicity and jet transverse momentum is reported for proton--proton collisions at a centre-of-mass energy of 7 TeV in the single-lepton channel. The data were collected with the ATLAS detector at the CERN Large Hadron Collider and comprise the full 2011 data sample corresponding to an integrated luminosity of 4.6 fb$^{-1}$. Differential cross-sections are presented as a function of the jet multiplicity for up to eight jets using jet transverse momentum thresholds of 25, 40, 60, and 80 GeV, and as a function of jet transverse momentum up to the fifth jet. The results are shown after background subtraction and corrections for all detector effects, within a kinematic range closely matched to the experimental acceptance. Several QCD-based Monte Carlo models are compared with the results. Sensitivity to the parton shower modelling is found at the higher jet multiplicities, at high transverse momentum of the leading jet and in the transverse momentum spectrum of the fifth leading jet. The MC@NLO+HERWIG MC is found to predict too few events at higher jet multiplicities.
Measurement of the $t\overline{t}$ cross-section as a function of the jet multiplicity for jets with $p_{\mathrm{T}}$ larger than 25 GeV. The uncertainties given correspond to the individual contributions of each source of systematic uncertainty as described in the paper.
Measurement of the $t\overline{t}$ cross-section as a function of the jet multiplicity for jets with $p_{\mathrm{T}}$ larger than 40 GeV. The uncertainties given correspond to the individual contributions of each source of systematic uncertainty as described in the paper.
Measurement of the $t\overline{t}$ cross-section as a function of the jet multiplicity for jets with $p_{\mathrm{T}}$ larger than 60 GeV. The uncertainties given correspond to the individual contributions of each source of systematic uncertainty as described in the paper.
Simultaneous measurements of the $t\bar{t}$, $W^+W^-$, and $Z/\gamma^{*}\rightarrow\tau\tau$ production cross-sections using an integrated luminosity of $4.6\,\mathrm{fb}^{-1}$ of $pp$ collisions at $\sqrt{s} = 7\,\mathrm{TeV}$ collected by the ATLAS detector at the LHC are presented. Events are selected with two high transverse momentum leptons consisting of an oppositely charged electron and muon pair. The three processes are separated using the distributions of the missing transverse momentum of events with zero and greater than zero jet multiplicities. Measurements of the fiducial cross-section are presented along with results that quantify for the first time the underlying correlations in the predicted and measured cross-sections due to proton parton distribution functions. These results indicate that the correlated NLO predictions for $t\bar{t}$ and $Z/\gamma^{*}\rightarrow\tau\tau$ underestimate the data, while those at NNLO generally describe the data well. The full cross-sections are measured to be $\sigma(t\bar{t}) = 181.2 \pm 2.8^{+9.7}_{-9.5} \pm 3.3 \pm 3.3\,\mathrm{pb}$, $\sigma(W^+W^-) = 53.3 \pm 2.7^{+7.3}_{-8.0} \pm 1.0 \pm 0.5\,\mathrm{pb}$, and $\sigma(Z/\gamma^{*}\rightarrow\tau\tau) = 1174 \pm 24^{+72}_{-87} \pm 21 \pm 9\,\mathrm{pb}$, where the cited uncertainties are due to statistics, systematic effects, luminosity and the LHC beam energy measurement, respectively. The $W^+W^-$ measurement includes the small contribution from Higgs boson decays, $H\rightarrow W^+W^-$.
Total $t\bar{t}$, $WW$, and $Z/\gamma^* \rightarrow \tau\tau$ cross-sections as measured simultaneously in this analysis with symmetrized uncertainties.
Measurements of normalized differential cross-sections for top-quark pair production are presented as a~function of the top-quark transverse momentum, and of the mass, transverse momentum, and rapidity of the $t\bar{t}$ system, in proton--proton collisions at a~center-of-mass energy of $\sqrt{s}$ = 7 TeV. The dataset corresponds to an integrated luminosity of 4.6 fb$^{-1}$, recorded in 2011 with the ATLAS detector at the CERN Large Hadron Collider. Events are selected in the lepton+jets channel, requiring exactly one lepton and at least four jets with at least one of the jets tagged as originating from a~$b$-quark. The measured spectra are corrected for detector efficiency and resolution effects and are compared to several Monte Carlo simulations and theory calculations. The results are in fair agreement with the predictions in a~wide kinematic range. Nevertheless, data distributions are softer than predicted for higher values of the mass of the $t\bar{t}$ system and of the top-quark transverse momentum. The measurements can also discriminate among different sets of parton distribution functions.
Normalized differential cross-sections for the hadronically decaying top-quark PT. The cross-section in each bin is given as the integral of the normalized differential cross-section over the bin width, divided by the bin width. The calculation of the cross-sections in the last bins includes events falling outside of the bin edges, and the normalization is done within the quoted bin width. The full covariance matrice is provided in Table 5 below.
Normalized differential cross-sections for the mass of the ttbar system. The cross-section in each bin is given as the integral of the normalized differential cross-section over the bin width, divided by the bin width. The calculation of the cross-sections in the last bins includes events falling outside of the bin edges, and the normalization is done within the quoted bin width. The full covariance matrice is provided in Table 6 below.
Normalized differential cross-sections for the PT of the ttbar system. The cross-section in each bin is given as the integral of the normalized differential cross-section over the bin width, divided by the bin width. The calculation of the cross-sections in the last bins includes events falling outside of the bin edges, and the normalization is done within the quoted bin width. The full covariance matrice is provided in Table 7 below.
The inclusive top quark pair ($t\bar{t}$) production cross-section $\sigma_{t\bar{t}}$ has been measured in $pp$ collisions at $\sqrt{s}=7$ TeV and $\sqrt{s}=8$ TeV with the ATLAS experiment at the LHC, using $t\bar{t}$ events with an opposite-charge $e\mu$ pair in the final state. The measurement was performed with the 2011 7 TeV dataset corresponding to an integrated luminosity of 4.6 fb$^{-1}$ and the 2012 8 TeV dataset of 20.3 fb$^{-1}$. The cross-section was measured to be: $\sigma_{t\bar{t}}=182.9\pm 3.1\pm 4.2\pm 3.6 \pm 3.3$ pb ($\sqrt{s}=7$ TeV) and $\sigma_{t\bar{t}}=242.9\pm 1.7\pm 5.5\pm 5.1\pm 4.2$ pb ($\sqrt{s}=8$ TeV, updated as described in the Addendum), where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the knowledge of the integrated luminosity and of the LHC beam energy. The results are consistent with recent theoretical QCD calculations at next-to-next-to-leading order. Fiducial measurements corresponding to the experimental acceptance of the leptons are also reported, together with the ratio of cross-sections measured at the two centre-of-mass energies. The inclusive cross-section results were used to determine the top quark pole mass via the dependence of the theoretically-predicted cross-section on $m_t^{\rm pole}$, giving a result of $m_t^{\rm pole}=172.9^{+2.5}_{-2.6}$ GeV. By looking for an excess of $t\bar{t}$ production with respect to the QCD prediction, the results were also used to place limits on the pair-production of supersymmetric top squarks $\tilde{t}_1$ with masses close to the top quark mass decaying via $\tilde{t}_1\rightarrow t\tilde{\chi}^0_1$ to predominantly right-handed top quarks and a light neutralino $\tilde{\chi}_0^1$, the lightest supersymmetric particle. Top squarks with masses between the top quark mass and 177 GeV are excluded at the 95% confidence level.
95% CL exclusion limit on signal strength.
95% CL exclusion limit on signal cross section for the 7 TeV dataset.
95% CL exclusion limit on signal cross section for the 8 TeV dataset.
The normalised differential top quark-antiquark production cross section is measured as a function of the jet multiplicity in proton-proton collisions at a centre-of-mass energy of 7 TeV at the LHC with the CMS detector. The measurement is performed in both the dilepton and lepton + jets decay channels using data corresponding to an integrated luminosity of 5.0 inverse femtobarns. Using a procedure to associate jets to decay products of the top quarks, the differential cross section of the t t-bar production is determined as a function of the additional jet multiplicity in the lepton + jets channel. Furthermore, the fraction of events with no additional jets is measured in the dilepton channel, as a function of the threshold on the jet transverse momentum. The measurements are compared with predictions from perturbative quantum chromodynamics and no significant deviations are observed.
Normalised differential TOP TOPBAR production cross section as a function of the jet multiplicity for jets with PT(JET) > 30 GeV in the dilepton channel. The statistical and main experimental and model systematic uncertainties are displayed.
Normalised differential TOP TOPBAR production cross section as a function of the jet multiplicity for jets with PT(JET) > 60 GeV in the dilepton channel. The statistical and main experimental and model systematic uncertainties are displayed.
Normalised differential TOP TOPBAR production cross section as a function of the jet multiplicity for jets with PT(JET) > 35 GeV in the lepton+jets channel. The statistical and main experimental and model systematic uncertainties are displayed.
The ratio of the top-quark branching fractions $R = B(t \to Wb)/B(t \to Wq)$, where the denominator includes the sum over all down-type quarks (q = b, s, d), is measured in the $t\bar{t}$ dilepton final state with proton-proton collision data at $\sqrt{s}$ = 8 TeV from an integrated luminosity of 19.7 inverse-femtobarns, collected with the CMS detector. In order to quantify the purity of the signal sample, the cross section is measured by fitting the observed jet multiplicity, thereby constraining the signal and background contributions. By counting the number of b jets per event, an unconstrained value of R = 1.014 $\pm$ 0.003 (stat) $\pm$ 0.032 (syst) is measured, in good agreement with the standard model prediction. A lower limit R greater than 0.955 at the 95% confidence level is obtained after requiring R lower than one, and a lower limit on the Cabibbo-Kobayashi-Maskawa matrix element |$V_tb$| greater than 0.975 is set at 95% confidence level. The result is combined with a previous CMS measurement of the t-channel single-top-quark cross section to determine the top-quark total decay width, $\Gamma_t$ = 1.36 $\pm$ 0.02 (stat)$^{+0.14}_{-0.11}$ (syst) GeV.
The measured TOP TOPBAR production cross section.
The measured ratio of branching fractions, R = BR(TOP --> W BOTTOM) / BR(TOP --> W QUARK) where the denominator includes the sum over all down-type quarks (QUARK = BOTTOM, STRANGE, DOWN). The combined measurement and the individual measurements from the three channels considered are presented.
An indirect measurement of the top-quark total decay width.
The t t-bar charge asymmetry in proton-proton collisions at sqrt(s) = 7 TeV is measured using the dilepton decay channel (ee, e mu, or mu mu). The data correspond to a total integrated luminosity of 5.0 inverse femtobarns, collected by the CMS experiment at the LHC. The t t-bar and lepton charge asymmetries, defined as the differences in absolute values of the rapidities between the reconstructed top quarks and antiquarks and of the pseudorapidities between the positive and negative leptons, respectively, are measured to be Ac = -0.010 +/- 0.017 (stat.) +/- 0.008 (syst.) and Ac[lep] = 0.009 +/- 0.010 (stat.) +/- 0.006 (syst). The lepton charge asymmetry is also measured as a function of the invariant mass, rapidity, and transverse momentum of the t t-bar system. All measurements are consistent with the expectations of the standard model.
The unfolded ASYMC and ASYMC(LEPTON) measurements.
Measurements of the unfolded ASYMC(LEPTON) values in bins of M(TOP TOPBAR).
Measurements of the unfolded ASYMC(LEPTON) values in bins of ABS(YRAP(TOP TOPBAR)).
The top-antitop quark (t t-bar) production cross section is measured in proton-proton collisions at sqrt(s) = 8 TeV with the CMS experiment at the LHC, using a data sample corresponding to an integrated luminosity of 5.3 inverse femtobarns. The measurement is performed by analysing events with a pair of electrons or muons, or one electron and one muon, and at least two jets, one of which is identified as originating from hadronisation of a bottom quark. The measured cross section is 239 +/- 2 (stat.) +/- 11 (syst.) +/- 6 (lum.) pb, for an assumed top-quark mass of 172.5 GeV, in agreement with the prediction of the standard model.
The total efficiencies etotal, i.e. the products of event acceptance, selection efficiency and branching fraction for the respective TOP TOPBAR final states, as estimated from simulation for a top-quark mass of 172.5 GeV, and the measured TOP TOPBAR production cross sections, where the uncertainties are from statistical, systematic and integrated luminosity components, respectively.
The TOP TOPBAR cross section obtained by combining all final states.
A search for baryon number violation (BNV) in top-quark decays is performed using pp collisions produced by the LHC at sqrt(s) = 8 TeV. The top-quark decay considered in this search results in one light lepton (muon or electron), two jets, but no neutrino in the final state. Data used for the analysis were collected by the CMS detector and correspond to an integrated luminosity of 19.5 inverse femtobarns. The event selection is optimized for top quarks produced in pairs, with one undergoing the BNV decay and the other the standard model hadronic decay to three jets. No significant excess of events over the expected yield from standard model processes is observed. The upper limits at 95% confidence level on the branching fraction of the BNV top-quark decay are calculated to be 0.0016 and 0.0017 for the muon and the electron channels, respectively. Assuming lepton universality, an upper limit of 0.0015 results from the combination of the two channels. These limits are the first that have been obtained on a BNV process involving the top quark.
Muon channel: expected and observed yields in the tight selections for an assumed BNV decay branching fraction of zero. The uncertainties include both statistical and systematic contributions.
Electron channel: expected and observed yields in the tight selections for an assumed BNV decay branching fraction of zero. The uncertainties include both statistical and systematic contributions.
Expected and observed 95% CL upper limits on the BNV decay branching fraction.
Forum