We present data on two-particle pseudorapidity and multiplicity correlations of charged particles for non single-diffractive\(p\bar p - collisions\) at c.m. energies of 200, 546 and 900 GeV. Pseudorapidity correlations interpreted in terms of a cluster model, which has been motivated by this and other experiments, require on average about two charged particles per cluster. The decay width of the clusters in pseudorapidity is approximately independent of multiplicity and of c.m. energy. The investigations of correlations in terms of pseudorapidity gaps confirm the picture of cluster production. The strength of forward-backward multiplicity correlations increases linearly with ins and depends strongly on position and size of the pseudorapidity gap separating the forward and backward interval. All our correlation studies can be understood in terms of a cluster model in which clusters contain on average about two charged particles, i.e. are of similar magnitude to earlier estimates from the ISR.
Results of a search for new physics in final states with an energetic jet and large missing transverse momentum are reported. The search uses proton-proton collision data corresponding to an integrated luminosity of 139 fb$^{-1}$ at a center-of-mass energy of 13 TeV collected in the period 2015-2018 with the ATLAS detector at the Large Hadron Collider. Compared to previous publications, in addition to an increase of almost a factor of four in the data size, the analysis implements a number of improvements in the signal selection and the background determination leading to enhanced sensitivity. Events are required to have at least one jet with transverse momentum above 150 GeV and no reconstructed leptons ($e$, $\mu$ or $\tau$) or photons. Several signal regions are considered with increasing requirements on the missing transverse momentum starting at 200 GeV. Overall agreement is observed between the number of events in data and the Standard Model predictions. Model-independent $95%$ confidence-level limits on visible cross sections for new processes are obtained in the range between 736 fb and 0.3 fb. Results are also translated into improved exclusion limits in models with pair-produced weakly interacting dark-matter candidates, large extra spatial dimensions, supersymmetric particles in several compressed scenarios, axion-like particles, and new scalar particles in dark-energy-inspired models. In addition, the data are translated into bounds on the invisible branching ratio of the Higgs boson.
This is the HEPData space for the ATLAS monojet full Run 2 analysis. The full resolution figures can be found at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2018-06/ The full statistical likelihood is provided for this analysis. It can be downloaded by clicking on the purple 'Resources' button above and selecting the 'Common Resources' category. <br/><br/> <b>Post-fit $p_{\mathrm{T}}^{\mathrm{recoil}}$ distribution:</b> <ul> <li><a href="102093?version=3&table=HistogramCR1mu0b">CR1mu0b</a> <li><a href="102093?version=3&table=HistogramCR1e0b">CR1e0b</a> <li><a href="102093?version=3&table=HistogramCR1L1b">CR1L1b</a> <li><a href="102093?version=3&table=HistogramCR2mu">CR2mu</a> <li><a href="102093?version=3&table=HistogramCR2e">CR2e</a> <li><a href="102093?version=3&table=HistogramSR">SR</a> </ul> <b>Exclusion contours:</b> <ul> <li>Dark Matter axial-vector mediator: <ul> <li><a href="102093?version=3&table=ContourobsDMA">observed</a> <li><a href="102093?version=3&table=Contourobs_p1DMA">+1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=Contourobs_m1DMA">-1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=ContourexpDMA">expected</a> <li><a href="102093?version=3&table=Contourexp_p1DMA">+1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourexp_m1DMA">-1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourexp_p2DMA">+2 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourexp_m2DMA">-2 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourobs_xsecDMA">observed upper limits on the cross-sections</a> </ul> <li>Dark Matter pseudo-scalar mediator: <ul> <li><a href="102093?version=3&table=ContourobsDMP">observed</a> <li><a href="102093?version=3&table=Contourobs_p1DMP">+1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=Contourobs_m1DMP">-1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=ContourexpDMP">expected</a> <li><a href="102093?version=3&table=Contourexp_p1DMP">+1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourexp_m1DMP">-1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourexp_p2DMP">+2 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourexp_m2DMP">-2 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourobs_xsecDMP">observed upper limits on the cross-sections</a> </ul> <li>Dark Matter vector mediator: <ul> <li><a href="102093?version=3&table=ContourobsDMV">observed</a> <li><a href="102093?version=3&table=Contourobs_p1DMV">+1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=Contourobs_m1DMV">-1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=ContourexpDMV">expected</a> <li><a href="102093?version=3&table=Contourexp_p1DMV">+1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourexp_m1DMV">-1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourexp_p2DMV">+2 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourexp_m2DMV">-2 $\sigma$ expected</a> </ul> <li>Dark Matter spin-dependent WIMP-nucleon scattering cross-section: <a href="102093?version=3&table=ContourSDneutron">observed</a> <li>Dark Matter spin-independent WIMP-nucleon scattering cross-section: <a href="102093?version=3&table=ContourSInucleon">observed</a> <li>Dark Matter WIMP annihilation rate: <a href="102093?version=3&table=ContourID">observed</a> <li>SUSY stop pair production: <ul> <li><a href="102093?version=3&table=Contourg_obsTT_directCC">observed</a> <li><a href="102093?version=3&table=Contourg_obs_p1TT_directCC">+1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=Contourg_obs_m1TT_directCC">-1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=Contourg_expTT_directCC">expected</a> <li><a href="102093?version=3&table=Contourg_exp_p1TT_directCC">+1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourg_exp_m1TT_directCC">-1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourg_exp_p2TT_directCC">+2 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourg_exp_m2TT_directCC">-2 $\sigma$ expected</a> </ul> <li>SUSY stop pair production (4-body decay): <ul> <li><a href="102093?version=3&table=Contourg_obsTT_bffN">observed</a> <li><a href="102093?version=3&table=Contourg_obs_p1TT_bffN">+1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=Contourg_obs_m1TT_bffN">-1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=Contourg_expTT_bffN">expected</a> <li><a href="102093?version=3&table=Contourg_exp_p1TT_bffN">+1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourg_exp_m1TT_bffN">-1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourg_exp_p2TT_bffN">+2 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourg_exp_m2TT_bffN">-2 $\sigma$ expected</a> </ul> <li>SUSY sbottom pair production: <ul> <li><a href="102093?version=3&table=Contourg_obsBB">observed</a> <li><a href="102093?version=3&table=Contourg_obs_p1BB">+1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=Contourg_obs_m1BB">-1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=Contourg_expBB">expected</a> <li><a href="102093?version=3&table=Contourg_exp_p1BB">+1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourg_exp_m1BB">-1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourg_exp_p2BB">+2 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourg_exp_m2BB">-2 $\sigma$ expected</a> </ul> <li>SUSY squark pair production: <ul> <li><a href="102093?version=3&table=Contourg_obsSS">observed</a> <li><a href="102093?version=3&table=Contourg_obs_p1SS">+1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=Contourg_obs_m1SS">-1 $\sigma_{\mathrm{theory}}^{\mathrm{PDF+scale}}$ observed</a> <li><a href="102093?version=3&table=Contourg_expSS">expected</a> <li><a href="102093?version=3&table=Contourg_exp_p1SS">+1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourg_exp_m1SS">-1 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourg_exp_p2SS">+2 $\sigma$ expected</a> <li><a href="102093?version=3&table=Contourg_exp_m2SS">-2 $\sigma$ expected</a> </ul> <li>Dark energy: <a href="102093?version=3&table=ContourDE">observed and expected</a> <li>ADD: <a href="102093?version=3&table=ContourADD">observed and expected</a> <li>Axion-like particles: <a href="102093?version=3&table=ContourALPs">observed and expected</a> </ul> <b>Impact of systematic uncertainties:</b> <a href="102093?version=3&table=Tablesystimpacts">Table</a><br/><br/> <b>Yields of exclusive regions:</b> <a href="102093?version=3&table=TableyieldsEM0">EM0</a> <a href="102093?version=3&table=TableyieldsEM1">EM1</a> <a href="102093?version=3&table=TableyieldsEM2">EM2</a> <a href="102093?version=3&table=TableyieldsEM3">EM3</a> <a href="102093?version=3&table=TableyieldsEM4">EM4</a> <a href="102093?version=3&table=TableyieldsEM5">EM5</a> <a href="102093?version=3&table=TableyieldsEM6">EM6</a> <a href="102093?version=3&table=TableyieldsEM7">EM7</a> <a href="102093?version=3&table=TableyieldsEM8">EM8</a> <a href="102093?version=3&table=TableyieldsEM9">EM9</a> <a href="102093?version=3&table=TableyieldsEM10">EM10</a> <a href="102093?version=3&table=TableyieldsEM11">EM11</a> <a href="102093?version=3&table=TableyieldsEM12">EM12</a><br/><br/> <b>Yields of inclusive regions:</b> <a href="102093?version=3&table=TableyieldsIM0">IM0</a> <a href="102093?version=3&table=TableyieldsIM1">IM1</a> <a href="102093?version=3&table=TableyieldsIM2">IM2</a> <a href="102093?version=3&table=TableyieldsIM3">IM3</a> <a href="102093?version=3&table=TableyieldsIM4">IM4</a> <a href="102093?version=3&table=TableyieldsIM5">IM5</a> <a href="102093?version=3&table=TableyieldsIM6">IM6</a> <a href="102093?version=3&table=TableyieldsIM7">IM7</a> <a href="102093?version=3&table=TableyieldsIM8">IM8</a> <a href="102093?version=3&table=TableyieldsIM9">IM9</a> <a href="102093?version=3&table=TableyieldsIM10">IM10</a> <a href="102093?version=3&table=TableyieldsIM11">IM11</a> <a href="102093?version=3&table=TableyieldsIM12">IM12</a><br/><br/> <b>Cutflows:</b><br/><br/> Signals filtered with a truth $E_\mathrm{T}^\mathrm{miss}$ cut at: <a href="102093?version=3&table=Tablecutflows150GeV">150 GeV</a> <a href="102093?version=3&table=Tablecutflows350GeV">350 GeV</a><br/><br/>
Using a data sample collected with the CLEO II detector at CESR, we have searched for dipion transitions between pairs of $\Upsilon$ resonances at energies near the $\Upsilon(4S)$. We obtain upper limits $B(\Upsilon(4S)\to \Upsilon(2S)\pi^+\pi^-) < 3.9 \times 10^{-4}$ and $B(\Upsilon(4S)\to \Upsilon(1S)\pi^+\pi^-) < 1.2 \times 10^{-4}$. We also observe the transitions $\Upsilon(3S)\to \Upsilon(1S)$, $\Upsilon(3S)\to \Upsilon(2S)$, and $\Upsilon(2S)\to \Upsilon(1S)$, from which we measure the cross-sections for the radiative processes $e^+e^- \to \Upsilon(3S)\gamma$ and $e^+e^- \to \Upsilon(2S)\gamma$.
We have observed a second sharp peak in the cross section for e+e−→hadrons at a center-of-mass energy of 3.695±0.004 GeV. The upper limit of the full width at half-maximum is 2.7 MeV.
We report measurement of the cross section of $e^+e^-\to \pi^+\pi^-\psi(2S)$ between 4.0 and $5.5 {\rm GeV}$, based on an analysis of initial state radiation events in a $980 \rm fb^{-1}$ data sample recorded with the Belle detector. The properties of the $Y(4360)$ and $Y(4660)$ states are determined. Fitting the mass spectrum of $\pi^+\pi^-\psi(2S)$ with two coherent Breit-Wigner functions, we find two solutions with identical mass and width but different couplings to electron-positron pairs: $M_{Y(4360)} = (4347\pm 6\pm 3) {\rm MeV}/c^2$, $\Gamma_{Y(4360)} = (103\pm 9\pm 5) {\rm MeV}$, $M_{Y(4660)} = (4652\pm10\pm 8) {\rm MeV}/c^2$, $\Gamma_{Y(4660)} = (68\pm 11\pm 1) \rm MeV$; and ${\cal{B}}[Y(4360)\to \pi^+\pi^-\psi(2S)]\cdot \Gamma_{Y(4360)}^{e^+e^-} = (10.9\pm 0.6\pm 0.7) \rm eV$ and ${\cal{B}}[Y(4660)\to \pi^+\pi^-\psi(2S)]\cdot \Gamma_{Y(4660)}^{e^+e^-} = (8.1\pm 1.1\pm 0.5) \rm eV$ for one solution; or ${\cal{B}}[Y(4360)\to \pi^+\pi^-\psi(2S)]\cdot \Gamma_{Y(4360)}^{e^+e^-} = (9.2\pm 0.6\pm 0.6) \rm eV$ and ${\cal{B}}[Y(4660)\to \pi^+\pi^-\psi(2S)]\cdot \Gamma_{Y(4660)}^{e^+e^-} = (2.0\pm 0.3\pm 0.2) \rm eV$ for the other. Here, the first errors are statistical and the second systematic. Evidence for a charged charmoniumlike structure at $4.05 {\rm GeV}/c^2$ is observed in the $\pi^{\pm}\psi(2S)$ intermediate state in the $Y(4360)$ decays.
We present a measurement of the $\ttbar$ differential cross section with respect to the $\ttbar$ invariant mass, dSigma/dMttbar, in $\ppbar$ collisions at $\sqrt{s}=1.96$ TeV using an integrated luminosity of $2.7\invfb$ collected by the CDF II experiment. The $\ttbar$ invariant mass spectrum is sensitive to a variety of exotic particles decaying into $\ttbar$ pairs. The result is consistent with the standard model expectation, as modeled by \texttt{PYTHIA} with \texttt{CTEQ5L} parton distribution functions.
Using data collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider, we measure the energy dependence of the $e^+e^- \to h_b(nP)\pi^+\pi^-$ $(n=1,2)$ cross sections from thresholds up to $11.02\,$GeV. We find clear $\Upsilon(10860)$ and $\Upsilon(11020)$ peaks with little or no continuum contribution. We study the resonant substructure of the $\Upsilon(11020) \to h_b(nP)\pi^+\pi^-$ transitions and find evidence that they proceed entirely via the intermediate isovector states $Z_b(10610)$ and $Z_b(10650)$. The relative fraction of these states is loosely constrained by the current data: the hypothesis that only $Z_b(10610)$ is produced is excluded at the level of 3.3 standard deviations, while the hypothesis that only $Z_b(10650)$ is produced is not excluded at a significant level.
Measurements of neutral pion production at midrapidity in sqrt(s_NN) = 200 GeV Au+Au collisions as a function of transverse momentum, p_T, collision centrality, and angle with respect to reaction plane are presented. The data represent the final pi^0 results from the PHENIX experiment for the first RHIC Au+Au run at design center-of-mass-energy. They include additional data obtained using the PHENIX Level-2 trigger with more than a factor of three increase in statistics over previously published results for p_T > 6 GeV/c. We evaluate the suppression in the yield of high-p_T pi^0's relative to point-like scaling expectations using the nuclear modification factor R_AA. We present the p_T dependence of R_AA for nine bins in collision centrality. We separately integrate R_AA over larger p_T bins to show more precisely the centrality dependence of the high-p_T suppression. We then evaluate the dependence of the high-p_T suppression on the emission angle \Delta\phi of the pions with respect to event reaction plane for 7 bins in collision centrality. We show that the yields of high-p_T pi^0's vary strongly with \Delta\phi, consistent with prior measurements. We show that this variation persists in the most peripheral bin accessible in this analysis. For the peripheral bins we observe no suppression for neutral pions produced aligned with the reaction plane while the yield of pi^0's produced perpendicular to the reaction plane is suppressed by more than a factor of 2. We analyze the combined centrality and \Delta\phi dependence of the pi^0 suppression in different p_T bins using different possible descriptions of parton energy loss dependence on jet path-length averages to determine whether a single geometric picture can explain the observed suppression pattern.
A search is conducted for a new scalar boson $S$, with a mass distinct from that of the Higgs boson, decaying into four leptons ($\ell =$$e$, $\mu$) via an intermediate state containing two on-shell, promptly decaying new spin-1 bosons $Z_\text{d}$: $S \rightarrow Z_\text{d}Z_\text{d} \rightarrow 4\ell$, where the $Z_\text{d}$ boson has a mass between 15 and 300 GeV, and the $S$ boson has a mass between either 30 and 115 GeV or 130 and 800 GeV. The search uses proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider with an integrated luminosity of 139 fb$^{-1}$ at a centre-of-mass energy of $\sqrt{s}=13$ TeV. No significant excess above the Standard Model background expectation is observed. Upper limits at 95% confidence level are set on the production cross-section times branching ratio, $\sigma(gg \to S) \times \mathcal{B}(S\rightarrow Z_\text{d}Z_\text{d} \rightarrow 4\ell)$, as a function of the mass of both particles, $m_S$ and $m_{Z\text{d}}$.
Charged hadrons in 0.15 < pt < 4 GeV/c associated with particles of pt^trig > 4 GeV/c are reconstructed in pp and Au+Au collisions at sqrt(s_NN)=200 GeV. The associated multiplicity and pt magnitude sum are found to increase from pp to central Au+Au collisions. The associated pt distributions, while similar in shape on the near side, are significantly softened on the away side in central Au+Au relative to pp and not much harder than that of inclusive hadrons. The results, consistent with jet quenching, suggest that the away-side fragments approach equilibration with the medium traversed.
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