This paper presents measurements of top-antitop quark pair ($t\bar{t}$) production in association with additional $b$-jets. The analysis utilises 140 fb$^{-1}$ of proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 13 TeV. Fiducial cross-sections are extracted in a final state featuring one electron and one muon, with at least three or four $b$-jets. Results are presented at the particle level for both integrated cross-sections and normalised differential cross-sections, as functions of global event properties, jet kinematics, and $b$-jet pair properties. Observable quantities characterising $b$-jets originating from the top quark decay and additional $b$-jets are also measured at the particle level, after correcting for detector effects. The measured integrated fiducial cross-sections are consistent with $t\bar{t}b\bar{b}$ predictions from various next-to-leading-order matrix element calculations matched to a parton shower within the uncertainties of the predictions. State-of-the-art theoretical predictions are compared with the differential measurements; none of them simultaneously describes all observables. Differences between any two predictions are smaller than the measurement uncertainties for most observables.
- - - - - - - - Overview of HEPData Record - - - - - - - - <br/><br/> ATLAS public webpage of paper: <a href="https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2019-03/">link</a><br/><br/> <b>Fiducial phase space definitions:</b><br/> <i>Particle level:</i> <ul> <li> Common: N E = N MU = 1, CHARGE E != CHARGE MU <li> NJETS >= 2, NBJETS >= 2 <li> NJETS >= 3, NBJETS >= 3 <li> NJETS >= 4, NBJETS >= 3 <li> NJETS >= 4, NBJETS >= 4 <li> NJETS >= 5, NBJETS >= 4 </ul><br/> <b>Objects definitions:</b> <ul> <li> LEP PT > 28 GeV, ABS ETARAP LEP < 2.5 <li> JET PT > 25 GeV, ABS ETARAP JET < 2.5, R JET = 0.4 <li> BJET: >=1 b-hadron with PT > 5 GeV is associated to the jet via ghost matching </ul><br/> <b>Particle level:</b><br/> <br/>Data from Table 06: <a href="153521?table="Fiducial xsec results>Fiducial xsec results </a><br/><br/> <u>1D:</u><br/> Data bootstraps: <ul> <li> Data from Figure 09: <a href="153521?table=Bootstrap $N_{b-jets}$ in $≥2b$">Bootstrap $N_{b-jets}$ in $≥2b$ </a> <li> Data from Figure 10a: <a href="153521?table=Bootstrap $N_{b-jets}$ in $≥3b$">Bootstrap $N_{b-jets}$ in $≥3b$ </a> <li> Data from Figure 10b: <a href="153521?table=Bootstrap $N_{c/l-jets}$ in $≥3b$">Bootstrap $N_{c/l-jets}$ in $≥3b$ </a> <li> Data from Figure 10c: <a href="153521?table=Bootstrap $H_{T}^{had}$ in $≥3b$">Bootstrap $H_{T}^{had}$ in $≥3b$ </a> <li> Data from Figure 10d: <a href="153521?table=Bootstrap $\Delta R_{avg}^{bb}$ in $≥3b$">Bootstrap $\Delta R_{avg}^{bb}$ in $≥3b$ </a> <li> Data from Figure 11a: <a href="153521?table=Bootstrap $p_{T}(b_{1})$ in $≥3b$">Bootstrap $p_{T}(b_{1})$ in $≥3b$ </a> <li> Data from Figure 11b: <a href="153521?table=Bootstrap $p_{T}(b_{2})$ in $≥3b$">Bootstrap $p_{T}(b_{2})$ in $≥3b$ </a> <li> Data from Figure 11c: <a href="153521?table=Bootstrap $p_{T}(b_{1}^{top})$ in $≥3b$">Bootstrap $p_{T}(b_{1}^{top})$ in $≥3b$ </a> <li> Data from Figure 11d: <a href="153521?table=Bootstrap $p_{T}(b_{2}^{top})$ in $≥3b$">Bootstrap $p_{T}(b_{2}^{top})$ in $≥3b$ </a> <li> Data from Figure 12a: <a href="153521?table=Bootstrap $p_{T}(b_{3})$ in $≥3b$">Bootstrap $p_{T}(b_{3})$ in $≥3b$ </a> <li> Data from Figure 12b: <a href="153521?table=Bootstrap $p_{T}(b_{1}^{add})$ in $≥3b$">Bootstrap $p_{T}(b_{1}^{add})$ in $≥3b$ </a> <li> Data from Figure 13a: <a href="153521?table=Bootstrap $m(b_{1}b_{2})$ in $≥3b$">Bootstrap $m(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Figure 13b: <a href="153521?table=Bootstrap $p_{T}(b_{1}b_{2})$ in $≥3b$">Bootstrap $p_{T}(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Figure 13c: <a href="153521?table=Bootstrap $m(bb^{top})$ in $≥3b$">Bootstrap $m(bb^{top})$ in $≥3b$ </a> <li> Data from Figure 13d: <a href="153521?table=Bootstrap $p_{T}(bb^{top})$ in $≥3b$">Bootstrap $p_{T}(bb^{top})$ in $≥3b$ </a> <li> Data from Figure 14a: <a href="153521?table=Bootstrap $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥3b$">Bootstrap $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥3b$ </a> <li> Data from Figure 14b: <a href="153521?table=Bootstrap $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥3b≥1l/c$">Bootstrap $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥3b≥1l/c$ </a> <li> Data from Figure 14c: <a href="153521?table=Bootstrap $p_{T}(l/c-jet_{1})$ in $≥3b≥1l/c$">Bootstrap $p_{T}(l/c-jet_{1})$ in $≥3b≥1l/c$ </a> <li> Data from Figure 14d: <a href="153521?table=Bootstrap $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥3b≥1l/c$">Bootstrap $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥3b≥1l/c$ </a> <li> Data from Figure 15a: <a href="153521?table=Bootstrap $m(bb^{min\Delta R})$ in $≥4b$">Bootstrap $m(bb^{min\Delta R})$ in $≥4b$ </a> <li> Data from Figure 15b: <a href="153521?table=Bootstrap $p_{T}(bb^{min\Delta R})$ in $≥4b$">Bootstrap $p_{T}(bb^{min\Delta R})$ in $≥4b$ </a> <li> Data from Figure 15c: <a href="153521?table=Bootstrap $m(bb^{add})$ in $≥4b$">Bootstrap $m(bb^{add})$ in $≥4b$ </a> <li> Data from Figure 15d: <a href="153521?table=Bootstrap $p_{T}(bb^{add})$ in $≥4b$">Bootstrap $p_{T}(bb^{add})$ in $≥4b$ </a> <li> Data from Figure 01a (aux): <a href="153521?table=Bootstrap $|\eta(b_{3})|$ in $≥3b$">Bootstrap $|\eta(b_{3})|$ in $≥3b$ </a> <li> Data from Figure 01b (aux): <a href="153521?table=Bootstrap $|\eta(b_{1}^{add})|$ in $≥3b$">Bootstrap $|\eta(b_{1}^{add})|$ in $≥3b$ </a> <li> Data from Figure 02a (aux): <a href="153521?table=Bootstrap $\Delta R(b_{1}b_{2})$ in $≥3b$">Bootstrap $\Delta R(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Figure 02b (aux): <a href="153521?table=Bootstrap $m(e\mu bb^{top})$ in $≥3b$">Bootstrap $m(e\mu bb^{top})$ in $≥3b$ </a> <li> Data from Figure 03a (aux): <a href="153521?table=Bootstrap $|\eta(l/c-jet_{1})|$ in $≥3b≥1l/c$">Bootstrap $|\eta(l/c-jet_{1})|$ in $≥3b≥1l/c$ </a> <li> Data from Figure 03b (aux): <a href="153521?table=Bootstrap $\Delta\eta_{max}^{jj}$ in $≥3b$">Bootstrap $\Delta\eta_{max}^{jj}$ in $≥3b$ </a> <li> Data from Figure 04a (aux): <a href="153521?table=Bootstrap $H_{T}^{all}$ in $≥3b$">Bootstrap $H_{T}^{all}$ in $≥3b$ </a> <li> Data from Figure 04b (aux): <a href="153521?table=Bootstrap $m(e\mu b_{1}b_{2})$ in $≥3b$">Bootstrap $m(e\mu b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Figure 05a (aux): <a href="153521?table=Bootstrap $|\eta(b_{1})|$ in $≥3b$">Bootstrap $|\eta(b_{1})|$ in $≥3b$ </a> <li> Data from Figure 05b (aux): <a href="153521?table=Bootstrap $|\eta(b_{2})|$ in $≥3b$">Bootstrap $|\eta(b_{2})|$ in $≥3b$ </a> <li> Data from Figure 05c (aux): <a href="153521?table=Bootstrap $|\eta(b_{1}^{top})|$ in $≥3b$">Bootstrap $|\eta(b_{1}^{top})|$ in $≥3b$ </a> <li> Data from Figure 05d (aux): <a href="153521?table=Bootstrap $|\eta(b_{2}^{top})|$ in $≥3b$">Bootstrap $|\eta(b_{2}^{top})|$ in $≥3b$ </a> <li> Data from Figure 06a (aux): <a href="153521?table=Bootstrap $p_{T}(b_{1})$ in $≥4b$">Bootstrap $p_{T}(b_{1})$ in $≥4b$ </a> <li> Data from Figure 06b (aux): <a href="153521?table=Bootstrap $p_{T}(b_{2})$ in $≥4b$">Bootstrap $p_{T}(b_{2})$ in $≥4b$ </a> <li> Data from Figure 06c (axu): <a href="153521?table=Bootstrap $p_{T}(b_{1}^{top})$ in $≥4b$">Bootstrap $p_{T}(b_{1}^{top})$ in $≥4b$ </a> <li> Data from Figure 06d (aux): <a href="153521?table=Bootstrap $p_{T}(b_{2}^{top})$ in $≥4b$">Bootstrap $p_{T}(b_{2}^{top})$ in $≥4b$ </a> <li> Data from Figure 07a (aux): <a href="153521?table=Bootstrap $p_{T}(b_{3})$ in $≥4b$">Bootstrap $p_{T}(b_{3})$ in $≥4b$ </a> <li> Data from Figure 07b (aux): <a href="153521?table=Bootstrap $p_{T}(b_{4})$ in $≥4b$">Bootstrap $p_{T}(b_{4})$ in $≥4b$ </a> <li> Data from Figure 07c (aux): <a href="153521?table=Bootstrap $p_{T}(b_{1}^{add})$ in $≥4b$">Bootstrap $p_{T}(b_{1}^{add})$ in $≥4b$ </a> <li> Data from Figure 07d (aux): <a href="153521?table=Bootstrap $p_{T}(b_{2}^{add})$ in $≥4b$">Bootstrap $p_{T}(b_{2}^{add})$ in $≥4b$ </a> <li> Data from Figure 08a (aux): <a href="153521?table=Bootstrap $m(b_{1}b_{2})$ in $≥4b$">Bootstrap $m(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Figure 08b (aux): <a href="153521?table=Bootstrap $p_{T}(b_{1}b_{2})$ in $≥4b$">Bootstrap $p_{T}(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Figure 09a (aux): <a href="153521?table=Bootstrap $m(bb^{top})$ in $≥4b$">Bootstrap $m(bb^{top})$ in $≥4b$ </a> <li> Data from Figure 09b (aux): <a href="153521?table=Bootstrap $p_{T}(bb^{top})$ in $≥4b$">Bootstrap $p_{T}(bb^{top})$ in $≥4b$ </a> <li> Data from Figure 10a (aux): <a href="153521?table=Bootstrap $H_{T}^{all}$ in $≥4b$">Bootstrap $H_{T}^{all}$ in $≥4b$ </a> <li> Data from Figure 10b (aux): <a href="153521?table=Bootstrap $m(e\mu b_{1}b_{2})$ in $≥4b$">Bootstrap $m(e\mu b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Figure 11a (aux): <a href="153521?table=Bootstrap $m(e\mu bb^{top})$ in $≥4b$">Bootstrap $m(e\mu bb^{top})$ in $≥4b$ </a> <li> Data from Figure 11b (aux): <a href="153521?table=Bootstrap $H_{T}^{had}$ in $≥4b$">Bootstrap $H_{T}^{had}$ in $≥4b$ </a> <li> Data from Figure 11c (aux): <a href="153521?table=Bootstrap min$\Delta R(bb)$ in $≥4b$">Bootstrap min$\Delta R(bb)$ in $≥4b$ </a> <li> Data from Figure 11d (aux): <a href="153521?table=Bootstrap $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥4b$">Bootstrap $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥4b$ </a> <li> Data from Figure 12a (aux): <a href="153521?table=Bootstrap $\Delta R_{avg}^{bb}$ in $≥4b$">Bootstrap $\Delta R_{avg}^{bb}$ in $≥4b$ </a> <li> Data from Figure 12b (aux): <a href="153521?table=Bootstrap $\Delta\eta_{max}^{jj}$ in $≥4b$">Bootstrap $\Delta\eta_{max}^{jj}$ in $≥4b$ </a> <li> Data from Figure 12c (aux): <a href="153521?table=Bootstrap $N_{l/c-jets}$ in $≥4b$">Bootstrap $N_{l/c-jets}$ in $≥4b$ </a> <li> Data from Figure 13a (aux): <a href="153521?table=Bootstrap $p_{T}(l/c-jet_{1})$ in $≥4b≥1l/c$">Bootstrap $p_{T}(l/c-jet_{1})$ in $≥4b≥1l/c$ </a> <li> Data from Figure 13b (aux): <a href="153521?table=Bootstrap $|\eta(l/c-jet_{1})|$ in $≥4b≥1l/c$">Bootstrap $|\eta(l/c-jet_{1})|$ in $≥4b≥1l/c$ </a> <li> Data from Figure 13c (aux): <a href="153521?table=Bootstrap $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥4b≥1l/c$">Bootstrap $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥4b≥1l/c$ </a> <li> Data from Figure 13d (aux): <a href="153521?table=Bootstrap $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥4b≥1l/c$">Bootstrap $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥4b≥1l/c$ </a> <li> Data from Figure 14a (aux): <a href="153521?table=Bootstrap $|\eta(b_{1})|$ in $≥4b$">Bootstrap $|\eta(b_{1})|$ in $≥4b$ </a> <li> Data from Figure 14b (aux): <a href="153521?table=Bootstrap $|\eta(b_{2})|$ in $≥4b$">Bootstrap $|\eta(b_{2})|$ in $≥4b$ </a> <li> Data from Figure 14c (aux): <a href="153521?table=Bootstrap $|\eta(b_{1}^{top})|$ in $≥4b$">Bootstrap $|\eta(b_{1}^{top})|$ in $≥4b$ </a> <li> Data from Figure 14d (aux): <a href="153521?table=Bootstrap $|\eta(b_{2}^{top})|$ in $≥4b$">Bootstrap $|\eta(b_{2}^{top})|$ in $≥4b$ </a> <li> Data from Figure 15a (aux): <a href="153521?table=Bootstrap $|\eta(b_{3})|$ in $≥4b$">Bootstrap $|\eta(b_{3})|$ in $≥4b$ </a> <li> Data from Figure 15b (aux): <a href="153521?table=Bootstrap $|\eta(b_{4})|$ in $≥4b$">Bootstrap $|\eta(b_{4})|$ in $≥4b$ </a> <li> Data from Figure 15c (aux): <a href="153521?table=Bootstrap $|\eta(b_{1}^{add})|$ in $≥4b$">Bootstrap $|\eta(b_{1}^{add})|$ in $≥4b$ </a> <li> Data from Figure 15d (aux): <a href="153521?table=Bootstrap $|\eta(b_{2}^{add})|$ in $≥4b$">Bootstrap $|\eta(b_{2}^{add})|$ in $≥4b$ </a> </ul><br/> Measurements: <ul> <li> Data from Table 01 (aux): <a href="153521?table=Diff. XS $N_{b-jets}$ in $≥2b$">Diff. XS $N_{b-jets}$ in $≥2b$ </a> <li> Data from Table 02 (aux): <a href="153521?table=Diff. XS $H_{T}^{had}$ in $≥3b$">Diff. XS $H_{T}^{had}$ in $≥3b$ </a> <li> Data from Table 03 (aux): <a href="153521?table=Diff. XS $H_{T}^{all}$ in $≥3b$">Diff. XS $H_{T}^{all}$ in $≥3b$ </a> <li> Data from Table 04 (aux): <a href="153521?table=Diff. XS $\Delta R_{avg}^{bb}$ in $≥3b$">Diff. XS $\Delta R_{avg}^{bb}$ in $≥3b$ </a> <li> Data from Table 05 (aux): <a href="153521?table=Diff. XS $\Delta\eta_{max}^{jj}$ in $≥3b$">Diff. XS $\Delta\eta_{max}^{jj}$ in $≥3b$ </a> <li> Data from Table 06 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1})$ in $≥3b$">Diff. XS $p_{T}(b_{1})$ in $≥3b$ </a> <li> Data from Table 07 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1}^{top})$ in $≥3b$">Diff. XS $p_{T}(b_{1}^{top})$ in $≥3b$ </a> <li> Data from Table 08 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{2})$ in $≥3b$">Diff. XS $p_{T}(b_{2})$ in $≥3b$ </a> <li> Data from Table 09 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{2}^{top})$ in $≥3b$">Diff. XS $p_{T}(b_{2}^{top})$ in $≥3b$ </a> <li> Data from Table 10 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{3})$ in $≥3b$">Diff. XS $p_{T}(b_{3})$ in $≥3b$ </a> <li> Data from Table 11 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1}^{add})$ in $≥3b$">Diff. XS $p_{T}(b_{1}^{add})$ in $≥3b$ </a> <li> Data from Table 12 (aux): <a href="153521?table=Diff. XS $|\eta(b_{1})|$ in $≥3b$">Diff. XS $|\eta(b_{1})|$ in $≥3b$ </a> <li> Data from Table 13 (aux): <a href="153521?table=Diff. XS $|\eta(b_{1}^{top})|$ in $≥3b$">Diff. XS $|\eta(b_{1}^{top})|$ in $≥3b$ </a> <li> Data from Table 14 (aux): <a href="153521?table=Diff. XS $|\eta(b_{2})|$ in $≥3b$">Diff. XS $|\eta(b_{2})|$ in $≥3b$ </a> <li> Data from Table 15 (aux): <a href="153521?table=Diff. XS $|\eta(b_{2}^{top})|$ in $≥3b$">Diff. XS $|\eta(b_{2}^{top})|$ in $≥3b$ </a> <li> Data from Table 16 (aux): <a href="153521?table=Diff. XS $|\eta(b_{3})|$ in $≥3b$">Diff. XS $|\eta(b_{3})|$ in $≥3b$ </a> <li> Data from Table 17 (aux): <a href="153521?table=Diff. XS $|\eta(b_{1}^{add})|$ in $≥3b$">Diff. XS $|\eta(b_{1}^{add})|$ in $≥3b$ </a> <li> Data from Table 18 (aux): <a href="153521?table=Diff. XS $m(b_{1}b_{2})$ in $≥3b$">Diff. XS $m(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 19 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1}b_{2})$ in $≥3b$">Diff. XS $p_{T}(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 20 (aux): <a href="153521?table=Diff. XS $m(bb^{top})$ in $≥3b$">Diff. XS $m(bb^{top})$ in $≥3b$ </a> <li> Data from Table 21 (aux): <a href="153521?table=Diff. XS $p_{T}(bb^{top})$ in $≥3b$">Diff. XS $p_{T}(bb^{top})$ in $≥3b$ </a> <li> Data from Table 22 (aux): <a href="153521?table=Diff. XS $m(e\mu b_{1}b_{2})$ in $≥3b$">Diff. XS $m(e\mu b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 23 (aux): <a href="153521?table=Diff. XS $m(e\mu bb^{top})$ in $≥3b$">Diff. XS $m(e\mu bb^{top})$ in $≥3b$ </a> <li> Data from Table 24 (aux): <a href="153521?table=Diff. XS $\Delta R(b_{1}b_{2})$ in $≥3b$">Diff. XS $\Delta R(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 25 (aux): <a href="153521?table=Diff. XS $N_{l/c-jets}$ in $≥3b$">Diff. XS $N_{l/c-jets}$ in $≥3b$ </a> <li> Data from Table 26 (aux): <a href="153521?table=Diff. XS $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥3b$">Diff. XS $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥3b$ </a> <li> Data from Table 27 (aux): <a href="153521?table=Diff. XS $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥3b$">Diff. XS $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥3b$ </a> <li> Data from Table 28 (aux): <a href="153521?table=Diff. XS $\Delta R(e\mu bb^{top},l/c-jet)$ in $≥3b≥1l/c$">Diff. XS $\Delta R(e\mu bb^{top},l/c-jet)$ in $≥3b≥1l/c$ </a> <li> Data from Table 29 (aux): <a href="153521?table=Diff. XS $p_{T}(l/c-jet_{1}) - p_{T}(b_{1}^{add})$ in $≥3b≥1l/c$">Diff. XS $p_{T}(l/c-jet_{1}) - p_{T}(b_{1}^{add})$ in $≥3b≥1l/c$ </a> <li> Data from Table 30 (aux): <a href="153521?table=Diff. XS $|\eta(l/c-jet_{1})|$ in $≥3b≥1l/c$">Diff. XS $|\eta(l/c-jet_{1})|$ in $≥3b≥1l/c$ </a> <li> Data from Table 31 (aux): <a href="153521?table=Diff. XS $p_{T}(l/c-jet_{1})$ in $≥3b≥1l/c$">Diff. XS $p_{T}(l/c-jet_{1})$ in $≥3b≥1l/c$ </a> <li> Data from Table 32 (aux): <a href="153521?table=Diff. XS $H_{T}^{had}$ in $≥4b$">Diff. XS $H_{T}^{had}$ in $≥4b$ </a> <li> Data from Table 33 (aux): <a href="153521?table=Diff. XS $H_{T}^{all}$ in $≥4b$">Diff. XS $H_{T}^{all}$ in $≥4b$ </a> <li> Data from Table 34 (aux): <a href="153521?table=Diff. XS $\Delta R_{avg}^{bb}$ in $≥4b$">Diff. XS $\Delta R_{avg}^{bb}$ in $≥4b$ </a> <li> Data from Table 35 (aux): <a href="153521?table=Diff. XS $\Delta\eta_{max}^{jj}$ in $≥4b$">Diff. XS $\Delta\eta_{max}^{jj}$ in $≥4b$ </a> <li> Data from Table 36 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1})$ in $≥4b$">Diff. XS $p_{T}(b_{1})$ in $≥4b$ </a> <li> Data from Table 37 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1}^{top})$ in $≥4b$">Diff. XS $p_{T}(b_{1}^{top})$ in $≥4b$ </a> <li> Data from Table 38 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{2})$ in $≥4b$">Diff. XS $p_{T}(b_{2})$ in $≥4b$ </a> <li> Data from Table 39 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{2}^{top})$ in $≥4b$">Diff. XS $p_{T}(b_{2}^{top})$ in $≥4b$ </a> <li> Data from Table 40 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{3})$ in $≥4b$">Diff. XS $p_{T}(b_{3})$ in $≥4b$ </a> <li> Data from Table 41 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1}^{add})$ in $≥4b$">Diff. XS $p_{T}(b_{1}^{add})$ in $≥4b$ </a> <li> Data from Table 42 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{4})$ in $≥4b$">Diff. XS $p_{T}(b_{4})$ in $≥4b$ </a> <li> Data from Table 43 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{2}^{add})$ in $≥4b$">Diff. XS $p_{T}(b_{2}^{add})$ in $≥4b$ </a> <li> Data from Table 44 (aux): <a href="153521?table=Diff. XS $|\eta(b_{1})|$ in $≥4b$">Diff. XS $|\eta(b_{1})|$ in $≥4b$ </a> <li> Data from Table 45 (aux): <a href="153521?table=Diff. XS $|\eta(b_{1}^{top})|$ in $≥4b$">Diff. XS $|\eta(b_{1}^{top})|$ in $≥4b$ </a> <li> Data from Table 46 (aux): <a href="153521?table=Diff. XS $|\eta(b_{2})|$ in $≥4b$">Diff. XS $|\eta(b_{2})|$ in $≥4b$ </a> <li> Data from Table 47 (aux): <a href="153521?table=Diff. XS $|\eta(b_{2}^{top})|$ in $≥4b$">Diff. XS $|\eta(b_{2}^{top})|$ in $≥4b$ </a> <li> Data from Table 48 (aux): <a href="153521?table=Diff. XS $|\eta(b_{3})|$ in $≥4b$">Diff. XS $|\eta(b_{3})|$ in $≥4b$ </a> <li> Data from Table 49 (aux): <a href="153521?table=Diff. XS $|\eta(b_{1}^{add})|$ in $≥4b$">Diff. XS $|\eta(b_{1}^{add})|$ in $≥4b$ </a> <li> Data from Table 50 (aux): <a href="153521?table=Diff. XS $|\eta(b_{4})|$ in $≥4b$">Diff. XS $|\eta(b_{4})|$ in $≥4b$ </a> <li> Data from Table 51 (aux): <a href="153521?table=Diff. XS $|\eta(b_{2}^{add})|$ in $≥4b$">Diff. XS $|\eta(b_{2}^{add})|$ in $≥4b$ </a> <li> Data from Table 52 (aux): <a href="153521?table=Diff. XS $m(b_{1}b_{2})$ in $≥4b$">Diff. XS $m(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 53 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1}b_{2})$ in $≥4b$">Diff. XS $p_{T}(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 54 (aux): <a href="153521?table=Diff. XS $m(bb^{top})$ in $≥4b$">Diff. XS $m(bb^{top})$ in $≥4b$ </a> <li> Data from Table 55 (aux): <a href="153521?table=Diff. XS $p_{T}(bb^{top})$ in $≥4b$">Diff. XS $p_{T}(bb^{top})$ in $≥4b$ </a> <li> Data from Table 56 (aux): <a href="153521?table=Diff. XS $m(e\mu b_{1}b_{2})$ in $≥4b$">Diff. XS $m(e\mu b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 57 (aux): <a href="153521?table=Diff. XS $m(e\mu bb^{top})$ in $≥4b$">Diff. XS $m(e\mu bb^{top})$ in $≥4b$ </a> <li> Data from Table 58 (aux): <a href="153521?table=Diff. XS $m(bb^{min\Delta R})$ in $≥4b$">Diff. XS $m(bb^{min\Delta R})$ in $≥4b$ </a> <li> Data from Table 59 (aux): <a href="153521?table=Diff. XS $p_{T}(bb^{min\Delta R})$ in $≥4b$">Diff. XS $p_{T}(bb^{min\Delta R})$ in $≥4b$ </a> <li> Data from Table 60 (aux): <a href="153521?table=Diff. XS $m(bb^{add})$ in $≥4b$">Diff. XS $m(bb^{add})$ in $≥4b$ </a> <li> Data from Table 61 (aux): <a href="153521?table=Diff. XS $p_{T}(bb^{add})$ in $≥4b$">Diff. XS $p_{T}(bb^{add})$ in $≥4b$ </a> <li> Data from Table 62 (aux): <a href="153521?table=Diff. XS $min\Delta R(bb)$ in $≥4b$">Diff. XS $min\Delta R(bb)$ in $≥4b$ </a> <li> Data from Table 63 (aux): <a href="153521?table=Diff. XS $\Delta R(b_{1}b_{2})$ in $≥4b$">Diff. XS $\Delta R(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 64 (aux): <a href="153521?table=Diff. XS $N_{l/c-jets}$ in $≥4b$">Diff. XS $N_{l/c-jets}$ in $≥4b$ </a> <li> Data from Table 65 (aux): <a href="153521?table=Diff. XS $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥4b$">Diff. XS $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥4b$ </a> <li> Data from Table 66 (aux): <a href="153521?table=Diff. XS $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥4b$">Diff. XS $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥4b$ </a> <li> Data from Table 67 (aux): <a href="153521?table=Diff. XS $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥4b≥1l/c$">Diff. XS $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥4b≥1l/c$ </a> <li> Data from Table 68 (aux): <a href="153521?table=Diff. XS $p_{T}(l/c-jet_{1}) - p_{T}(b_{1}^{add})$ in $≥4b≥1l/c$">Diff. XS $p_{T}(l/c-jet_{1}) - p_{T}(b_{1}^{add})$ in $≥4b≥1l/c$ </a> <li> Data from Table 69 (aux): <a href="153521?table=Diff. XS $|\eta(l/c-jet_{1})|$ in $≥4b≥1l/c$">Diff. XS $|\eta(l/c-jet_{1})|$ in $≥4b≥1l/c$ </a> <li> Data from Table 70 (aux): <a href="153521?table=Diff. XS $p_{T}(l/c-jet_{1})$ in $≥4b≥1l/c$">Diff. XS $p_{T}(l/c-jet_{1})$ in $≥4b≥1l/c$ </a> </ul><br/> <u>2D:</u><br/> Correlation matrices: <ul> <li> Data from Table 71 (aux): <a href="153521?table=Corr. mtrx $N_{b-jets}$ in $≥2b$">Corr. mtrx $N_{b-jets}$ in $≥2b$ </a> <li> Data from Table 72 (aux): <a href="153521?table=Corr. mtrx $N_{b-jets}$ in $≥3b$">Corr. mtrx $N_{b-jets}$ in $≥3b$ </a> <li> Data from Table 73 (aux): <a href="153521?table=Corr. mtrx $H_{T}^{had}$ in $≥3b$">Corr. mtrx $H_{T}^{had}$ in $≥3b$ </a> <li> Data from Table 74 (aux): <a href="153521?table=Corr. mtrx $H_{T}^{all}$ in $≥3b$">Corr. mtrx $H_{T}^{all}$ in $≥3b$ </a> <li> Data from Table 75 (aux): <a href="153521?table=Corr. mtrx $\Delta R_{avg}^{bb}$ in $≥3b$">Corr. mtrx $\Delta R_{avg}^{bb}$ in $≥3b$ </a> <li> Data from Table 76 (aux): <a href="153521?table=Corr. mtrx $\Delta\eta_{max}^{jj}$ in $≥3b$">Corr. mtrx $\Delta\eta_{max}^{jj}$ in $≥3b$ </a> <li> Data from Table 77 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1})$ in $≥3b$">Corr. mtrx $p_{T}(b_{1})$ in $≥3b$ </a> <li> Data from Table 78 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1}^{top})$ in $≥3b$">Corr. mtrx $p_{T}(b_{1}^{top})$ in $≥3b$ </a> <li> Data from Table 79 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{2})$ in $≥3b$">Corr. mtrx $p_{T}(b_{2})$ in $≥3b$ </a> <li> Data from Table 80 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{2}^{top})$ in $≥3b$">Corr. mtrx $p_{T}(b_{2}^{top})$ in $≥3b$ </a> <li> Data from Table 81 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{3})$ in $≥3b$">Corr. mtrx $p_{T}(b_{3})$ in $≥3b$ </a> <li> Data from Table 82 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1}^{add})$ in $≥3b$">Corr. mtrx $p_{T}(b_{1}^{add})$ in $≥3b$ </a> <li> Data from Table 83 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{1})|$ in $≥3b$">Corr. mtrx $|\eta(b_{1})|$ in $≥3b$ </a> <li> Data from Table 84 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{1}^{top})|$ in $≥3b$">Corr. mtrx $|\eta(b_{1}^{top})|$ in $≥3b$ </a> <li> Data from Table 85 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{2})|$ in $≥3b$">Corr. mtrx $|\eta(b_{2})|$ in $≥3b$ </a> <li> Data from Table 86 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{2}^{top})|$ in $≥3b$">Corr. mtrx $|\eta(b_{2}^{top})|$ in $≥3b$ </a> <li> Data from Table 87 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{3})|$ in $≥3b$">Corr. mtrx $|\eta(b_{3})|$ in $≥3b$ </a> <li> Data from Table 88 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{1}^{add})|$ in $≥3b$">Corr. mtrx $|\eta(b_{1}^{add})|$ in $≥3b$ </a> <li> Data from Table 89 (aux): <a href="153521?table=Corr. mtrx $m(b_{1}b_{2})$ in $≥3b$">Corr. mtrx $m(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 90 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1}b_{2})$ in $≥3b$">Corr. mtrx $p_{T}(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 91 (aux): <a href="153521?table=Corr. mtrx $m(bb^{top})$ in $≥3b$">Corr. mtrx $m(bb^{top})$ in $≥3b$ </a> <li> Data from Table 92 (aux): <a href="153521?table=Corr. mtrx $p_{T}(bb^{top})$ in $≥3b$">Corr. mtrx $p_{T}(bb^{top})$ in $≥3b$ </a> <li> Data from Table 93 (aux): <a href="153521?table=Corr. mtrx $m(e\mu b_{1}b_{2})$ in $≥3b$">Corr. mtrx $m(e\mu b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 94 (aux): <a href="153521?table=Corr. mtrx $m(e\mu bb^{top})$ in $≥3b$">Corr. mtrx $m(e\mu bb^{top})$ in $≥3b$ </a> <li> Data from Table 95 (aux): <a href="153521?table=Corr. mtrx $\Delta R(b_{1}b_{2})$ in $≥3b$">Corr. mtrx $\Delta R(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 96 (aux): <a href="153521?table=Corr. mtrx $N_{l/c-jets}$ in $≥3b$">Corr. mtrx $N_{l/c-jets}$ in $≥3b$ </a> <li> Data from Table 97 (aux): <a href="153521?table=Corr. mtrx $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥3b$">Corr. mtrx $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥3b$ </a> <li> Data from Table 98 (aux): <a href="153521?table=Corr. mtrx $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥3b$">Corr. mtrx $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥3b$ </a> <li> Data from Table 99 (aux): <a href="153521?table=Corr. mtrx $\Delta R(e\mu bb^{top},l/c-jet)$ in $≥3b≥1l/c$">Corr. mtrx $\Delta R(e\mu bb^{top},l/c-jet)$ in $≥3b≥1l/c$ </a> <li> Data from Table 100 (aux): <a href="153521?table=Corr. mtrx $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥3b≥1l/c$">Corr. mtrx $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥3b≥1l/c$ </a> <li> Data from Table 101 (aux): <a href="153521?table=Corr. mtrx $|\eta(l/c-jet_{1})|$ in $≥3b≥1l/c$">Corr. mtrx $|\eta(l/c-jet_{1})|$ in $≥3b≥1l/c$ </a> <li> Data from Table 102 (aux): <a href="153521?table=Corr. mtrx $p_{T}(l/c-jet_{1})$ in $≥3b≥1l/c$">Corr. mtrx $p_{T}(l/c-jet_{1})$ in $≥3b≥1l/c$ </a> <li> Data from Table 103 (aux): <a href="153521?table=Corr. mtrx $H_{T}^{had}$ in $≥4b$">Corr. mtrx $H_{T}^{had}$ in $≥4b$ </a> <li> Data from Table 104 (aux): <a href="153521?table=Corr. mtrx $H_{T}^{all}$ in $≥4b$">Corr. mtrx $H_{T}^{all}$ in $≥4b$ </a> <li> Data from Table 105 (aux): <a href="153521?table=Corr. mtrx $\Delta R_{avg}^{bb}$ in $≥4b$">Corr. mtrx $\Delta R_{avg}^{bb}$ in $≥4b$ </a> <li> Data from Table 106 (aux): <a href="153521?table=Corr. mtrx $\Delta\eta_{max}^{jj}$ in $≥4b$">Corr. mtrx $\Delta\eta_{max}^{jj}$ in $≥4b$ </a> <li> Data from Table 107 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1})$ in $≥4b$">Corr. mtrx $p_{T}(b_{1})$ in $≥4b$ </a> <li> Data from Table 108 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1}^{top})$ in $≥4b$">Corr. mtrx $p_{T}(b_{1}^{top})$ in $≥4b$ </a> <li> Data from Table 109 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{2})$ in $≥4b$">Corr. mtrx $p_{T}(b_{2})$ in $≥4b$ </a> <li> Data from Table 110 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{2}^{top})$ in $≥4b$">Corr. mtrx $p_{T}(b_{2}^{top})$ in $≥4b$ </a> <li> Data from Table 111 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{3})$ in $≥4b$">Corr. mtrx $p_{T}(b_{3})$ in $≥4b$ </a> <li> Data from Table 112 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1}^{add})$ in $≥4b$">Corr. mtrx $p_{T}(b_{1}^{add})$ in $≥4b$ </a> <li> Data from Table 113 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{4})$ in $≥4b$">Corr. mtrx $p_{T}(b_{4})$ in $≥4b$ </a> <li> Data from Table 114 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{2}^{add})$ in $≥4b$">Corr. mtrx $p_{T}(b_{2}^{add})$ in $≥4b$ </a> <li> Data from Table 115 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{1})|$ in $≥4b$">Corr. mtrx $|\eta(b_{1})|$ in $≥4b$ </a> <li> Data from Table 116 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{1}^{top})|$ in $≥4b$">Corr. mtrx $|\eta(b_{1}^{top})|$ in $≥4b$ </a> <li> Data from Table 117 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{2})|$ in $≥4b$">Corr. mtrx $|\eta(b_{2})|$ in $≥4b$ </a> <li> Data from Table 118 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{2}^{top})|$ in $≥4b$">Corr. mtrx $|\eta(b_{2}^{top})|$ in $≥4b$ </a> <li> Data from Table 119 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{3})|$ in $≥4b$">Corr. mtrx $|\eta(b_{3})|$ in $≥4b$ </a> <li> Data from Table 120 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{1}^{add})|$ in $≥4b$">Corr. mtrx $|\eta(b_{1}^{add})|$ in $≥4b$ </a> <li> Data from Table 121 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{4})|$ in $≥4b$">Corr. mtrx $|\eta(b_{4})|$ in $≥4b$ </a> <li> Data from Table 122 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{2}^{add})|$ in $≥4b$">Corr. mtrx $|\eta(b_{2}^{add})|$ in $≥4b$ </a> <li> Data from Table 123 (aux): <a href="153521?table=Corr. mtrx $m(b_{1}b_{2})$ in $≥4b$">Corr. mtrx $m(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 124 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1}b_{2})$ in $≥4b$">Corr. mtrx $p_{T}(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 125 (aux): <a href="153521?table=Corr. mtrx $m(bb^{top})$ in $≥4b$">Corr. mtrx $m(bb^{top})$ in $≥4b$ </a> <li> Data from Table 126 (aux): <a href="153521?table=Corr. mtrx $p_{T}(bb^{top})$ in $≥4b$">Corr. mtrx $p_{T}(bb^{top})$ in $≥4b$ </a> <li> Data from Table 127 (aux): <a href="153521?table=Corr. mtrx $m(e\mu b_{1}b_{2})$ in $≥4b$">Corr. mtrx $m(e\mu b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 128 (aux): <a href="153521?table=Corr. mtrx $m(e\mu bb^{top})$ in $≥4b$">Corr. mtrx $m(e\mu bb^{top})$ in $≥4b$ </a> <li> Data from Table 129 (aux): <a href="153521?table=Corr. mtrx $m(bb^{min\Delta R})$ in $≥4b$">Corr. mtrx $m(bb^{min\Delta R})$ in $≥4b$ </a> <li> Data from Table 130 (aux): <a href="153521?table=Corr. mtrx $p_{T}(bb^{min\Delta R})$ in $≥4b$">Corr. mtrx $p_{T}(bb^{min\Delta R})$ in $≥4b$ </a> <li> Data from Table 131 (aux): <a href="153521?table=Corr. mtrx $m(bb^{add})$ in $≥4b$">Corr. mtrx $m(bb^{add})$ in $≥4b$ </a> <li> Data from Table 132 (aux): <a href="153521?table=Corr. mtrx $p_{T}(bb^{add})$ in $≥4b$">Corr. mtrx $p_{T}(bb^{add})$ in $≥4b$ </a> <li> Data from Table 133 (aux): <a href="153521?table=Corr. mtrx min$\Delta R(bb)$ in $≥4b$">Corr. mtrx min$\Delta R(bb)$ in $≥4b$ </a> <li> Data from Table 134 (aux): <a href="153521?table=Corr. mtrx $\Delta R(b_{1}b_{2})$ in $≥4b$">Corr. mtrx $\Delta R(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 135 (aux): <a href="153521?table=Corr. mtrx $N_{l/c-jets}$ in $≥4b$">Corr. mtrx $N_{l/c-jets}$ in $≥4b$ </a> <li> Data from Table 136 (aux): <a href="153521?table=Corr. mtrx $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥4b$">Corr. mtrx $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥4b$ </a> <li> Data from Table 137 (aux): <a href="153521?table=Corr. mtrx $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥4b$">Corr. mtrx $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥4b$ </a> <li> Data from Table 138 (aux): <a href="153521?table=Corr. mtrx $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥4b≥1l/c$">Corr. mtrx $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥4b≥1l/c$ </a> <li> Data from Table 139 (aux): <a href="153521?table=Corr. mtrx $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥4b≥1l/c$">Corr. mtrx $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥4b≥1l/c$ </a> <li> Data from Table 140 (aux): <a href="153521?table=Corr. mtrx $|\eta(l/c-jet_{1})|$ in $≥4b≥1l/c$">Corr. mtrx $|\eta(l/c-jet_{1})|$ in $≥4b≥1l/c$ </a> <li> Data from Table 141 (aux): <a href="153521?table=Corr. mtrx $p_{T}(l/c-jet_{1})$ in $≥4b≥1l/c$">Corr. mtrx $p_{T}(l/c-jet_{1})$ in $≥4b≥1l/c$ </a> </ul><br/>
Measured and predicted fiducial cross-section results for additional b-jet production in four phase-space regions. The dashes (–) indicate that the predictions are not available. The differences between the various MC generator predictions are smaller than the size of theoretical uncertainties (20%–50%, not presented here) in the predictions.
Data bootstraps post unfolding for the normalised differential cross-section in the phase space with at least two $b$-jets as a function of the number of $b$-jets compared with predictions. The replicas are obtained by reweighting each observed data event by a random integer generated according to Poisson statistics, using the BootstrapGenerator software package (https://gitlab.cern.ch/atlas-physics/sm/StandardModelTools_BootstrapGenerator/BootstrapGenerator), which implements a technique described in ATL-PHYS-PUB-2021-011 (https://cds.cern.ch/record/2759945). The ATLAS event number and run number of each event are used as seed to uniquely but reproducibly initialise the random number generator for each event. The last bin contains the overflow.
A search for a light charged Higgs boson produced in decays of the top quark, $t \to H^\pm b$ with $H^\pm \to cs$, is presented. This search targets the production of top-quark pairs $t\bar{t} \to Wb H^\pm b$, with $W \to \ell\nu$ ($\ell = e, \mu$), resulting in a lepton-plus-jets final state characterised by an isolated electron or muon and at least four jets. The search exploits $b$-quark and $c$-quark identification techniques as well as multivariate methods to suppress the dominant $t\bar{t}$ background. The data analysed correspond to 140 $\text{fb}^{-1}$ of $pp$ collisions at $\sqrt{s} = 13$ TeV recorded with the ATLAS detector at the LHC between 2015 and 2018. Observed (expected) 95% confidence-level upper limits on the branching fraction $\mathscr{B}(t\to H^\pm b)$, assuming $\mathscr{B}(t\to Wb) + \mathscr{B}(t \to H^\pm (\to cs)b)=1.0$, are set between 0.066% (0.077%) and 3.6% (2.3%) for a charged Higgs boson with a mass between 60 GeV and 168 GeV.
Distributions of the dijet mass. The processes $t\bar{t}$(allHad), $tW$, Single top, $t\bar{t}H$, Other top, $W$ + jets, $Z$ + jets, and $VV$ listed are combined with the multijet background in the ‘Other’ category. The uncertainty band represents the combined statistical and systematic uncertainty of the prediction. Overlaid are the shapes for the $H^{\pm}_{80}$ and $H^{\pm}_{150}$ signal samples normalised to the total background prediction.
Data and background yields after the background-only fit of the BDT-score distribution for the $130\,$GeV signal mass BDT training. For comparison, the expected signal yield for $\mathscr{B}_{H^{\pm}}=1.0\%$ is added.
Observed (solid line) and expected (dotted line) upper limits on $\mathscr{B}_{H^{\pm}}$ for charged Higgs boson with masses between $60\,$GeV and $168\,$GeV, assuming $\mathscr{B}(t \to H^{\pm}(\to cs) b) = 1.0$. The $\pm 1 \sigma$ and $\pm 2 \sigma$ variations around the expected upper limit are indicated by the green and yellow bands, respectively.
A search for neutral long-lived particles (LLPs) decaying in the ATLAS hadronic calorimeter using 140 fb$^{-1}$ of proton-proton collisions at $\sqrt{s}=13$ TeV delivered by the LHC is presented. The analysis is composed of three channels. The first targets pair-produced LLPs, where at least one LLP is produced with sufficiently low boost that its decay products can be resolved as separate jets. The second and third channels target LLPs respectively produced in association with a $W$ or $Z$ boson that decays leptonically. In each channel, different search regions target different kinematic regimes, to cover a broad range of LLP mass hypotheses and models. No excesses of events relative to the background predictions are observed. Higgs boson branching fractions to pairs of hadronically decaying neutral LLPs larger than 1% are excluded at 95% confidence level for proper decay lengths in the range of 30 cm to 4.5 m depending on the LLP mass, a factor of three improvement on previous searches in the hadronic calorimeter. The production of long-lived dark photons in association with a $Z$ boson with cross-sections above 0.1 pb is excluded for dark photon mean proper decay lengths in the range of 20 cm to 50 m, improving previous ATLAS results by an order of magnitude. Finally, long-lived photo-phobic axion-like particle models are probed for the first time by ATLAS, with production cross-sections above 0.1 pb excluded in the 0.1 mm to 10 m range.
Observed (solid line) and expected (dashed line) upper limits at the 95% CL on the cross-section times branching fraction as a function of cτ for a selection of HS signal models in the CalR+2J channel for HS models with mediator masses of (a) 125 GeV, (b) 600 GeV and (c) 1000 GeV.
Observed (solid line) and expected (dashed line) upper limits at the 95% CL on the cross-section times branching fraction as a function of cτ for a selection of HS signal models in the CalR+2J channel for HS models with mediator masses of (a) 125 GeV, (b) 600 GeV and (c) 1000 GeV.
Observed (solid line) and expected (dashed line) upper limits at the 95% CL on the cross-section times branching fraction as a function of cτ for a selection of HS signal models in the CalR+2J channel for HS models with mediator masses of (a) 125 GeV, (b) 600 GeV and (c) 1000 GeV.
High-energy nuclear collisions create a quark-gluon plasma, whose initial condition and subsequent expansion vary from event to event, impacting the distribution of the event-wise average transverse momentum ($P([p_{\mathrm{T}}])$). Distinguishing between contributions from fluctuations in the size of the nuclear overlap area (geometrical component) and other sources at fixed size (intrinsic component) presents a challenge. Here, these two components are distinguished by measuring the mean, variance, and skewness of $P([p_{\mathrm{T}}])$ in $^{208}$Pb+$^{208}$Pb and $^{129}$Xe+$^{129}$Xe collisions at $\sqrt{s_{{\mathrm{NN}}}} = 5.02$ and 5.44 TeV, respectively, using the ATLAS detector at the LHC. All observables show distinct changes in behavior in ultra-central collisions, where the geometrical variations are suppressed as the overlap area reaches its maximum. These results demonstrate a new technique to disentangle geometrical and intrinsic fluctuations, enabling constraints on initial condition and properties of the quark-gluon plasma, such as the speed of sound.
Data from Figure 1, panel a, $\left\langle[p_{T}]\right\rangle$ vs $N_{ch}$ for Pb+Pb collisions, 0.5 $ <p_{T}< $ 5 GeV/c, $|\eta|< $ 2.5
Data from Figure 1, panel b, $\left\langle[p_{T}]\right\rangle$ vs $N_{ch}$ for Pb+Pb collisions, 0.5 $ <p_{T}< $ 5 GeV/c, $|\eta|< $ 2.5
Data from Figure 1, panel b, $\left\langle[p_{T}]\right\rangle$ vs $N_{ch}$ for Xe+Xe collisions, 0.5 $ <p_{T}< $ 5 GeV/c, $|\eta|< $ 2.5
This paper presents a search for exotic decays of the Higgs boson into a pair of new pseudoscalar particles, $H\rightarrow aa$, where one pseudoscalar decays into a $b$-quark pair and the other decays into a $\tau$-lepton pair, in the mass range $12\leq m_{a}\leq 60$ GeV. The analysis uses $pp$ collision data at $\sqrt{s} = 13$ TeV collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 140 ${fb}^{-1}$. No significant excess above the Standard Model (SM) prediction is observed. Assuming the SM Higgs boson production cross-section, the search sets upper limits at 95% confidence level on the branching ratio of Higgs bosons decaying into $b\bar{b}\tau^+\tau^-$, $\mathcal{B}(H \rightarrow aa \rightarrow b\bar{b}\tau^+\tau^-)$, between 2.2% and 3.9% depending on the pseudoscalar mass.
Visible mass $m^{\mathrm{vis}}(\mu\tau_{\mathrm{had}})$ and distribution for signal and the expected background. In order to compare the shapes, the expected signal distribution is shown assuming ten times the production cross section of the Higgs boson and a 100% branching ratio to $b\bar{b}\tau^+\tau^-$. Overflow events are included in the last bins.
Sum of the transverse mass $\Sigma m_T$ distributions for signal and the expected background. Events with high $m^{\mathrm{vis}}(\mu\tau_{\mathrm{had}})$ and high $\Sigma m_T$ are included in the $t\bar{t}$ region. In order to compare the shapes, the expected signal distribution is shown assuming ten times the production cross section of the Higgs boson and a 100% branching ratio to $b\bar{b}\tau^+\tau^-$. Overflow events are included in the last bins.
The pNN input variable visible mass $m^{\mathrm{vis}}(\mu\tau_{\mathrm{had}})$ is shown in the SR with no cut on the pNN discriminant. The signal shape is normalized to the same integral as the total background prediction. Overflow events are included in the last bins.
This Letter presents results from a combination of searches for Higgs boson pair production using 126$-$140 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}=13$ TeV recorded with the ATLAS detector. At 95% confidence level (CL), the upper limit on the production rate is 2.9 times the standard model (SM) prediction, with an expected limit of 2.4 assuming no Higgs boson pair production. Constraints on the Higgs boson self-coupling modifier $\kappa_{\lambda}=\lambda_{HHH}/\lambda_{HHH}^\mathrm{SM}$, and the quartic $HHVV$ coupling modifier $\kappa_{2V}=g_{HHVV}/g_{HHVV}^\mathrm{SM}$, are derived individually, fixing the other parameter to its SM value. The observed 95% CL intervals are $-1.2 < \kappa_{\lambda} < 7.2$ and $0.6 < \kappa_{2V} < 1.5$, respectively, while the expected intervals are $-1.6 < \kappa_{\lambda} < 7.2$ and $0.4 < \kappa_{2V} < 1.6$ in the SM case. Constraints obtained for several interaction parameters within Higgs effective field theory are the strongest to date, offering insights into potential deviations from SM predictions.
Observed and expected 95% CL upper limits on the signal strength for inclusive ggF HH and VBF HH production from the bb̄τ<sup>+</sup>τ<sup>-</sup>, bb̄γγ, bb̄bb̄, multilepton and bb̄ℓℓ+E<sub>T</sub><sup>miss</sup> decay channels, and their statistical combination. The predicted SM cross-section assumes m<sub>H</sub> = 125 GeV. The expected limit, along with its associated ±1σ and ±2σ bands, is calculated for the assumption of no HH production and with all NPs profiled to the observed data.
Expected value of the test statistic (-2ln$\Lambda$), as a function of the $\kappa_\lambda$ parameter for $b\bar{b}b\bar{b}$.
Expected value of the test statistic (-2ln$\Lambda$), as a function of the $\kappa_\lambda$ parameter for $b\bar{b}\tau\tau$.
A combination of fifteen top quark mass measurements performed by the ATLAS and CMS experiments at the LHC is presented. The data sets used correspond to an integrated luminosity of up to 5 and 20$^{-1}$ of proton-proton collisions at center-of-mass energies of 7 and 8 TeV, respectively. The combination includes measurements in top quark pair events that exploit both the semileptonic and hadronic decays of the top quark, and a measurement using events enriched in single top quark production via the electroweak $t$-channel. The combination accounts for the correlations between measurements and achieves an improvement in the total uncertainty of 31% relative to the most precise input measurement. The result is $m_\mathrm{t}$ = 172.52 $\pm$ 0.14 (stat) $\pm$ 0.30 (syst) GeV, with a total uncertainty of 0.33 GeV.
Uncertainties on the $m_{t}$ values extracted in the LHC, ATLAS, and CMS combinations arising from the categories described in the text, sorted in order of decreasing value of the combined LHC uncertainty.
Measurements of the suppression and correlations of dijets is performed using 3 $\mu$b$^{-1}$ of Xe+Xe data at $\sqrt{s_{\mathrm{NN}}} = 5.44$ TeV collected with the ATLAS detector at the LHC. Dijets with jets reconstructed using the $R=0.4$ anti-$k_t$ algorithm are measured differentially in jet $p_{\text{T}}$ over the range of 32 GeV to 398 GeV and the centrality of the collisions. Significant dijet momentum imbalance is found in the most central Xe+Xe collisions, which decreases in more peripheral collisions. Results from the measurement of per-pair normalized and absolutely normalized dijet $p_{\text{T}}$ balance are compared with previous Pb+Pb measurements at $\sqrt{s_{\mathrm{NN}}} =5.02$ TeV. The differences between the dijet suppression in Xe+Xe and Pb+Pb are further quantified by the ratio of pair nuclear-modification factors. The results are found to be consistent with those measured in Pb+Pb data when compared in classes of the same event activity and when taking into account the difference between the center-of-mass energies of the initial parton scattering process in Xe+Xe and Pb+Pb collisions. These results should provide input for a better understanding of the role of energy density, system size, path length, and fluctuations in the parton energy loss.
The centrality intervals in Xe+Xe collisions and their corresponding TAA with absolute uncertainties.
The centrality intervals in Xe+Xe and Pb+Pb collisions for matching SUM ET FCAL intervals and respective TAA values for Xe+Xe collisions.
The performance of the jet energy scale (JES) for jets with $|y| < 2.1$ evaluated as a function of pT_truth in different centrality bins. Simulated hard scatter events were overlaid onto events from a dedicated sample of minimum-bias Xe+Xe data.
Inclusive and differential measurements of the top-antitop ($t\bar{t}$) charge asymmetry $A_\text{C}^{t\bar{t}}$ and the leptonic asymmetry $A_\text{C}^{\ell\bar{\ell}}$ are presented in proton-proton collisions at $\sqrt{s} = 13$ TeV recorded by the ATLAS experiment at the CERN Large Hadron Collider. The measurement uses the complete Run 2 dataset, corresponding to an integrated luminosity of 139 fb$^{-1}$, combines data in the single-lepton and dilepton channels, and employs reconstruction techniques adapted to both the resolved and boosted topologies. A Bayesian unfolding procedure is performed to correct for detector resolution and acceptance effects. The combined inclusive $t\bar{t}$ charge asymmetry is measured to be $A_\text{C}^{t\bar{t}} = 0.0068 \pm 0.0015$, which differs from zero by 4.7 standard deviations. Differential measurements are performed as a function of the invariant mass, transverse momentum and longitudinal boost of the $t\bar{t}$ system. Both the inclusive and differential measurements are found to be compatible with the Standard Model predictions, at next-to-next-to-leading order in quantum chromodynamics perturbation theory with next-to-leading-order electroweak corrections. The measurements are interpreted in the framework of the Standard Model effective field theory, placing competitive bounds on several Wilson coefficients.
- - - - - - - - Overview of HEPData Record - - - - - - - - <br/><br/> <b>Results:</b> <ul> <li><a href="132116?version=2&table=Resultsforchargeasymmetryinclusive">$A_C^{t\bar{t}}$</a> <li><a href="132116?version=2&table=Resultsforchargeasymmetryvsmtt">$A_C^{t\bar{t}}$ vs $m_{t\bar{t}}$</a> <li><a href="132116?version=2&table=Resultsforchargeasymmetryvspttt">$A_C^{t\bar{t}}$ vs $p_{T,t\bar{t}}$</a> <li><a href="132116?version=2&table=Resultsforchargeasymmetryvsbetatt">$A_C^{t\bar{t}}$ vs $\beta_{z,t\bar{t}}$</a> <li><a href="132116?version=2&table=Resultsforleptonicchargeasymmetryinclusive">$A_C^{\ell\bar{\ell}}$</a> <li><a href="132116?version=2&table=Resultsforchargeasymmetryvsllmll">$A_C^{\ell\bar{\ell}}$ vs $m_{\ell\bar{\ell}}$</a> <li><a href="132116?version=2&table=Resultsforchargeasymmetryvsllptll">$A_C^{\ell\bar{\ell}}$ vs $p_{T,\ell\bar{\ell}}$</a> <li><a href="132116?version=2&table=Resultsforchargeasymmetryvsllbetall">$A_C^{\ell\bar{\ell}}$ vs $\beta_{z,\ell\bar{\ell}}$</a> </ul> <b>Bounds on the Wilson coefficients:</b> <ul> <li><a href="132116?version=2&table=BoundsonWilsoncoefficientschargeasymmetryinclusive">$A_C^{t\bar{t}}$</a> <li><a href="132116?version=2&table=BoundsonWilsoncoefficientschargeasymmetryvsmtt">$A_C^{t\bar{t}}$ vs $m_{t\bar{t}}$</a> </ul> <b>Ranking of systematic uncertainties:</b></br> Inclusive:<a href="132116?version=2&table=NPrankingchargeasymmetryinclusive">$A_C^{t\bar{t}}$</a></br> <b>$A_C^{t\bar{t}}$ vs $\beta_{z,t\bar{t}}$:</b> <ul> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsbetattbin0">$\beta_{z,t\bar{t}} \in[0,0.3]$</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsbetattbin1">$\beta_{z,t\bar{t}} \in[0.3,0.6]$</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsbetattbin2">$\beta_{z,t\bar{t}} \in[0.6,0.8]$</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsbetattbin3">$\beta_{z,t\bar{t}} \in[0.8,1]$</a> </ul> <b>$A_C^{t\bar{t}}$ vs $m_{t\bar{t}}$:</b> <ul> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsmttbin0">$m_{t\bar{t}}$ < $500$GeV</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsmttbin1">$m_{t\bar{t}} \in [500,750]$GeV</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsmttbin2">$m_{t\bar{t}} \in [750,1000]$GeV</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsmttbin3">$m_{t\bar{t}} \in [1000,1500]$GeV</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsmttbin4">$m_{t\bar{t}}$ > $1500$GeV</a> </ul> <b>$A_C^{t\bar{t}}$ vs $p_{T,t\bar{t}}$:</b> <ul> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsptttbin0">$p_{T,t\bar{t}} \in [0,30]$GeV</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsptttbin1">$p_{T,t\bar{t}} \in[30,120]$GeV</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsptttbin2">$p_{T,t\bar{t}}$ > $120$GeV</a> </ul> Inclusive leptonic:<a href="132116?version=2&table=NPrankingleptonicchargeasymmetryinclusive">$A_C^{\ell\bar{\ell}}$</a></br> <b>$A_C^{\ell\bar{\ell}}$ vs $\beta_{z,\ell\bar{\ell}}$</b> <ul> <li><a href="132116?version=2&tableNPrankingchargeasymmetry=vsllbetallbin0">$\beta_{z,\ell\bar{\ell}} \in [0,0.3]$</a> <li><a href="132116?version=2&tableNPrankingchargeasymmetry=vsllbetallbin1">$\beta_{z,\ell\bar{\ell}} \in [0.3,0.6]$</a> <li><a href="132116?version=2&tableNPrankingchargeasymmetry=vsllbetallbin2">$\beta_{z,\ell\bar{\ell}} \in [0.6,0.8]$</a> <li><a href="132116?version=2&tableNPrankingchargeasymmetry=vsllbetallbin3">$\beta_{z,\ell\bar{\ell}} \in [0.8,1]$</a> </ul> <b>$A_C^{\ell\bar{\ell}}$ vs $m_{\ell\bar{\ell}}$</b> <ul> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsllmllbin0">$m_{\ell\bar{\ell}}$ < $200$GeV</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsllmllbin1">$m_{\ell\bar{\ell}} \in [200,300]$GeV</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsllmllbin2">$m_{\ell\bar{\ell}} \in [300,400]$Ge$</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsllmllbin3">$m_{\ell\bar{\ell}}$ > $400$GeV</a> </ul> <b>$A_C^{\ell\bar{\ell}}$ vs $p_{T,\ell\bar{\ell}}$</b> <ul> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsllptllbin0">$p_{T,\ell\bar{\ell}}\in [0,20]$GeV</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsllptllbin1">$p_{T,\ell\bar{\ell}}\in[20,70]$GeV</a> <li><a href="132116?version=2&table=NPrankingchargeasymmetryvsllptllbin2">$p_{T,\ell\bar{\ell}}$ > $70$GeV</a> </ul> <b>NP correlations:</b> <ul> <li><a href="132116?version=2&table=NPcorrelationschargeasymmetryinclusive">$A_C^{t\bar{t}}$</a> <li><a href="132116?version=2&table=NPcorrelationschargeasymmetryvsmtt">$A_C^{t\bar{t}}$ vs $m_{t\bar{t}}$</a> <li><a href="132116?version=2&table=NPcorrelationschargeasymmetryvspttt">$A_C^{t\bar{t}}$ vs $p_{T,t\bar{t}}$</a> <li><a href="132116?version=2&table=NPcorrelationschargeasymmetryvsbetatt">$A_C^{t\bar{t}}$ vs $\beta_{z,t\bar{t}}$</a> <li><a href="132116?version=2&table=NPcorrelationsleptonicchargeasymmetryinclusive">$A_c^{\ell\bar{\ell}}$</a> <li><a href="132116?version=2&table=NPcorrelationschargeasymmetryvsllmll">$A_c^{\ell\bar{\ell}}$ vs $m_{\ell\bar{\ell}}$</a> <li><a href="132116?version=2&table=NPcorrelationschargeasymmetryvsllptll">$A_C^{\ell\bar{\ell}}$ vs $p_{T,\ell\bar{\ell}}$</a> <li><a href="132116?version=2&table=NPcorrelationschargeasymmetryvsllbetall">$A_C^{\ell\bar{\ell}}$ vs $\beta_{z,\ell\bar{\ell}}$</a> </ul> <b>Covariance matrices:</b> <ul> <li><a href="132116?version=2&table=Covariancematrixchargeasymmetryvsmtt">$A_C^{t\bar{t}}$ vs $m_{t\bar{t}}$</a> <li><a href="132116?version=2&table=Covariancematrixchargeasymmetryvspttt">$A_C^{t\bar{t}}$ vs $p_{T,t\bar{t}}$</a> <li><a href="132116?version=2&table=Covariancematrixchargeasymmetryvsbetatt">$A_C^{t\bar{t}}$ vs $\beta_{z,t\bar{t}}$</a> <li><a href="132116?version=2&table=Covariancematrixleptonicchargeasymmetryvsllmll">$A_c^{\ell\bar{\ell}}$ vs $m_{\ell\bar{\ell}}$</a> <li><a href="132116?version=2&table=Covariancematrixleptonicchargeasymmetryvsllptll">$A_C^{\ell\bar{\ell}}$ vs $p_{T,\ell\bar{\ell}}$</a> <li><a href="132116?version=2&table=Covariancematrixleptonicchargeasymmetryvsllbetall">$A_C^{\ell\bar{\ell}}$ vs $\beta_{z,\ell\bar{\ell}}$</a> </ul>
The unfolded inclusive charge asymmetry. The measured values are given with statistical and systematic uncertainties. The SM theory predictions calculated at NNLO in QCD and NLO in EW theory are listed, and the impact of the linear term of the Wilson coefficient on the $A_C^{t\bar{t}}$ prediction is shown for two different values. The scale uncertainty is obtained by varying renormalisation and factorisation scales independently by a factor of 2 or 0.5 around $\mu_0$ to calculate the maximum and minimum value of the asymmetry, respectively. The nominal value $\mu_0$ is chosen as $H_T/4$. The variations in which one scale is multiplied by 2 while the other scale is divided by 2 are excluded. Finally, the scale and MC integration uncertainties are added in quadrature.
The unfolded differential charge asymmetry as a function of the invariant mass of the top pair system. The measured values are given with statistical and systematic uncertainties. The SM theory predictions calculated at NNLO in QCD and NLO in EW theory are listed, and the impact of the linear term of the Wilson coefficient on the $A_C^{t\bar{t}}$ prediction is shown for two different values. The scale uncertainty is obtained by varying renormalisation and factorisation scales independently by a factor of 2 or 0.5 around $\mu_0$ to calculate the maximum and minimum value of the asymmetry, respectively. The nominal value $\mu_0$ is chosen as $H_T/4$. The variations in which one scale is multiplied by 2 while the other scale is divided by 2 are excluded. Finally, the scale and MC integration uncertainties are added in quadrature.
A combination of measurements of the inclusive top-quark pair production cross-section performed by ATLAS and CMS in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV at the LHC is presented. The cross-sections are obtained using top-quark pair decays with an opposite-charge electron-muon pair in the final state and with data corresponding to an integrated luminosity of about 5 fb$^{-1}$ at $\sqrt{s}=7$ TeV and about 20 fb$^{-1}$ at $\sqrt{s}=8$ TeV for each experiment. The combined cross-sections are determined to be $178.5 \pm 4.7$ pb at $\sqrt{s}=7$ TeV and $243.3^{+6.0}_{-5.9}$ pb at $\sqrt{s}=8$ TeV with a correlation of 0.41, using a reference top-quark mass value of 172.5 GeV. The ratio of the combined cross-sections is determined to be $R_{8/7}= 1.363\pm 0.032$. The combined measured cross-sections and their ratio agree well with theory calculations using several parton distribution function (PDF) sets. The values of the top-quark pole mass (with the strong coupling fixed at 0.118) and the strong coupling (with the top-quark pole mass fixed at 172.5 GeV) are extracted from the combined results by fitting a next-to-next-to-leading-order plus next-to-next-to-leading-log QCD prediction to the measurements. Using a version of the NNPDF3.1 PDF set containing no top-quark measurements, the results obtained are $m_t^\text{pole} = 173.4^{+1.8}_{-2.0}$ GeV and $\alpha_\text{s}(m_Z)= 0.1170^{+ 0.0021}_{-0.0018}$.
Full covariance matrix including all systematic uncertainties expressed as nuisance parameters. With the exception of the cross section parameters, all parameters were normalised to 1 before the fit. Therefore, the diagonal elements represent the constraint in quadrature.
Full covariance matrix including all systematic uncertainties expressed as nuisance parameters. With the exception of the cross section parameters, all parameters were normalised to 1 before the fit. Therefore, the diagonal elements represent the constraint in quadrature.