Date

Electroweak production of two jets in association with a Z boson in proton-proton collisions at $\sqrt{s}= $ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Eur.Phys.J.C 78 (2018) 589, 2018.
Inspire Record 1645246 DOI 10.17182/hepdata.85867

A measurement of the electroweak (EW) production of two jets in association with a Z boson in proton-proton collisions at $\sqrt{s} = $ 13 TeV is presented, based on data recorded in 2016 by the CMS experiment at the LHC corresponding to an integrated luminosity of 35.9 fb$^{-1}$. The measurement is performed in the $\ell\ell\mathrm{jj}$ final state with $\ell$ including electrons and muons, and the jets j corresponding to the quarks produced in the hard interaction. The measured cross section in a kinematic region defined by invariant masses $m_{\ell\ell} > $ 50 GeV, $m_{\mathrm{jj}} > $ 120 GeV, and transverse momenta $p_{\mathrm{T j}} > $ 25 GeV is $\sigma_\mathrm{EW}(\ell\ell\mathrm{jj})= $ 552 $\pm$ 19 (stat) $\pm$ 55 (syst) fb, in agreement with leading-order standard model predictions. The final state is also used to perform a search for anomalous trilinear gauge couplings. No evidence is found and limits on anomalous trilinear gauge couplings associated with dimension-six operators are given in the framework of an effective field theory. The corresponding 95% confidence level intervals are $-2.6 < c_{WWW}/\Lambda^2 < 2.6 $ TeV$^{-2}$ and $-8.4 < c_{W}/\Lambda^2 < 10.1 $ TeV$^{-2}$. The additional jet activity of events in a signal-enriched region is also studied, and the measurements are in agreement with predictions.

14 data tables

One-dimensional limits on the ATGC EFT parameters at 95% CL

One-dimensional limits on the ATGC effective Lagrangian (LEP parametrization) parameters at 95% CL

The best fit signal strength for dielectron, dimuon and combined dilepton channels. The measurement is performed in a kinematic region defined by invariant masses $m_{ll}~>~50$ GeV, $m_{jj}~>~120$ GeV, and transverse momenta $p_{Tj}~>~25$ GeV, where $l$ denotes electrons and muons, and $j$ - quarks produced in the hard interaction.

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Measurement of the cross section for isolated-photon plus jet production in $pp$ collisions at $\sqrt s=13$ TeV using the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Lett.B 780 (2018) 578-602, 2018.
Inspire Record 1645627 DOI 10.17182/hepdata.78401

The dynamics of isolated-photon production in association with a jet in proton-proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb$^{-1}$. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti-$k_t$ algorithm with radius parameter $R=0.4$ and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon-jet invariant mass and the scattering angle in the photon-jet centre-of-mass system. Tree-level plus parton-shower predictions from SHERPA and PYTHIA as well as next-to-leading-order QCD predictions from JETPHOX and SHERPA are compared to the measurements.

5 data tables

Measured cross sections for isolated-photon plus jet production as a function of $E_{\rm T}^{\gamma}$.

Measured cross sections for isolated-photon plus jet production as a function of $p_{\rm T}^{\rm jet-lead}$.

Measured cross sections for isolated-photon plus jet production as a function of $\Delta\phi^{\rm \gamma-jet\ lead}$.

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Search for decays of stopped exotic long-lived particles produced in proton-proton collisions at $\sqrt{s}=$ 13 TeV

The CMS collaboration Sirunyan, A.M. ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 05 (2018) 127, 2018.
Inspire Record 1645630 DOI 10.17182/hepdata.83010

A search is presented for the decays of heavy exotic long-lived particles (LLPs) that are produced in proton-proton collisions at a center-of-mass energy of 13 TeV at the CERN LHC and come to rest in the CMS detector. Their decays would be visible during periods of time well separated from proton-proton collisions. Two decay scenarios of stopped LLPs are explored: a hadronic decay detected in the calorimeter and a decay into muons detected in the muon system. The calorimeter (muon) search covers a period of sensitivity totaling 721 (744) hours in 38.6 (39.0) fb$^{-1}$ of data collected by the CMS detector in 2015 and 2016. The results are interpreted in several scenarios that predict LLPs. Production cross section limits are set as a function of the mean proper lifetime and the mass of the LLPs, for lifetimes between 100 ns and 10 days. These are the most stringent limits to date on the mass of hadronically decaying stopped LLPs, and this is the first search at the LHC for stopped LLPs that decay to muons.

33 data tables

The $\Delta t_{\text{DT}}$ distribution for 2016 data, MC simulated cosmic ray muon, 1000 GeV gluino signal, and 600 GeV MCHAMP signal events, for the muon search. The events plotted pass a subset of the full analysis selection that is designed to select good-quality DSA muon tracks but does not reject the cosmic ray muon background. The number of cosmic ray muon background events is greatly reduced when the full selection is applied, as we require $\Delta t_{\text{DT}}>-20$ ns and $\Delta t_{\text{RPC}}>-7.5$ ns. The histograms are normalized to unit area.

The $\Delta t_{\text{RPC}}$ distribution for 2016 data, MC simulated cosmic ray muon, 1000 GeV gluino signal, and 600 GeV MCHAMP signal events, for the muon search. The events plotted pass a subset of the full analysis selection that is designed to select good-quality DSA muon tracks but does not reject the cosmic ray muon background. The number of cosmic ray muon background events is greatly reduced when the full selection is applied, as we require $\Delta t_{\text{DT}}>-20$ ns and $\Delta t_{\text{RPC}}>-7.5$ ns. The histograms are normalized to unit area.

The $\varepsilon_{\text{reco}}$ values as a function of $E_{g}$, for $\tilde{g}$ R-hadrons that stop in the EB or HB, in the MC simulation, for the calorimeter search. The $\varepsilon_{\text{reco}}$ values are plotted for the two-body gluino decay, when $m_{\tilde{g}}$ is 600 GeV.

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Version 2
Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ collisions at $\sqrt{s}=13\,$ TeV using the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Rev.D 98 (2018) 012003, 2018.
Inspire Record 1646686 DOI 10.17182/hepdata.81709

Measurements are made of differential cross-sections of highly boosted pair-produced top quarks as a function of top-quark and $t\bar{t}$ system kinematic observables using proton--proton collisions at a center-of-mass energy of $\sqrt{s} = 13$ TeV. The data set corresponds to an integrated luminosity of $36.1$ fb$^{-1}$, recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. Events with two large-radius jets in the final state, one with transverse momentum $p_{\rm T} > 500$ GeV and a second with $p_{\rm T}>350$ GeV, are used for the measurement. The top-quark candidates are separated from the multijet background using jet substructure information and association with a $b$-tagged jet. The measured spectra are corrected for detector effects to a particle-level fiducial phase space and a parton-level limited phase space, and are compared to several Monte Carlo simulations by means of calculated $\chi^2$ values. The cross-section for $t\bar{t}$ production in the fiducial phase-space region is $292 \pm 7 \ \rm{(stat)} \pm 76 \rm{(syst)}$ fb, to be compared to the theoretical prediction of $384 \pm 36$ fb.

173 data tables

inclusive absolute differential cross-section at particle level

$p_{T}^{t,1}$ absolute differential cross-section at particle level

$|{y}^{t,1}|$ absolute differential cross-section at particle level

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Observation of medium induced modifications of jet fragmentation in PbPb collisions using isolated-photon-tagged jets

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 121 (2018) 242301, 2018.
Inspire Record 1648162 DOI 10.17182/hepdata.80817

Measurements of fragmentation functions for jets associated with an isolated photon are presented for the first time in pp and PbPb collisions. The analysis uses data collected with the CMS detector at the CERN LHC at a nucleon-nucleon center-of-mass energy of 5.02 TeV. Fragmentation functions are obtained for jets with p$_\mathrm{T}^\text{jet} >$ 30 GeV in events containing an isolated photon with p$_\mathrm{T}^\gamma>$ 60 GeV, using charged tracks with transverse momentum p$_\mathrm{T}^\text{trk} >$ 1 GeV in a cone around the jet axis. The association with an isolated photon constrains the initial p$_\mathrm{T}$ and azimuthal angle of the parton whose shower produced the jet. For central PbPb collisions, modifications of the jet fragmentation functions are observed when compared to those measured in pp collisions, while no significant differences are found in the 50% most peripheral collisions. Jets in central PbPb events show an excess (depletion) of low (high) p$_\mathrm{T}$ particles, with a transition around 3 GeV.

16 data tables

$\xi^\mathrm{jet}$ distributions for jets associated with an isolated photon in pp and 50-100% centrality PbPb collisions. The resolutions of the measured jet energy and azimuthal angle in pp are smeared to match those in the PbPb sample.

$\xi^\mathrm{jet}$ distributions for jets associated with an isolated photon in pp and 30-50% centrality PbPb collisions. The resolutions of the measured jet energy and azimuthal angle in pp are smeared to match those in the PbPb sample.

$\xi^\mathrm{jet}$ distributions for jets associated with an isolated photon in pp and 10-30% centrality PbPb collisions. The resolutions of the measured jet energy and azimuthal angle in pp are smeared to match those in the PbPb sample.

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Neutral pion and $\eta$ meson production in p-Pb collisions at $\mathbf{\sqrt{s_{\rm NN}}} = 5.02$ TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adolfsson, Jonatan ; et al.
Eur.Phys.J.C 78 (2018) 624, 2018.
Inspire Record 1649235 DOI 10.17182/hepdata.83700

Neutral pion and $\eta$ meson invariant differential yields were measured in non-single diffractive p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV with the ALICE experiment at the CERN LHC. The analysis combines results from three complementary photon measurements, utilizing the PHOS and EMCal calorimeters and the Photon Conversion Method. The invariant differential yields of $\pi^0$ and $\eta$ meson inclusive production are measured near mid-rapidity in a broad transverse momentum range of $0.3 4$ GeV/$c$ at $0.483\pm 0.015_{\rm stat}\pm 0.015_{\rm sys}$. A deviation from $m_{\rm T}$ scaling is observed for $p_{\rm T}<2$ GeV/$c$. The measured $\eta$/$\pi^{0}$ ratio is consistent with previous measurements from proton-nucleus and pp collisions over the full $p_{\rm T}$ range. The measured $\eta$/$\pi^{0}$ ratio at high $p_{\rm T}$ also agrees within uncertainties with measurements from nucleus-nucleus collisions. The $\pi^0$ and $\eta$ yields in p-Pb relative to the scaled pp interpolated reference, $R_{\rm pPb}$, are presented for $0.3

6 data tables

Invariant differential yield of PI0 produced in NSD p-Pp collisions with centre-of-mass energy/nucleon 5.02 TeV.

Invariant differential yields of ETA produced in NSD p-Pb collisions with centre-of-mass energy/nucleon 5.02 TeV.

The measured ratio of invariant yields for inclusive ETA to PI0 production at a centre-of-mass energy/nucleon 5.02 TeV.

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Version 3
A search for high-mass resonances decaying to $\tau\nu$ in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Rev.Lett. 120 (2018) 161802, 2018.
Inspire Record 1649273 DOI 10.17182/hepdata.80812

A search for high-mass resonances decaying to $\tau\nu$ using proton-proton collisions at $\sqrt{s}$ = 13 TeV produced by the Large Hadron Collider is presented. Only $\tau$-lepton decays with hadrons in the final state are considered. The data were recorded with the ATLAS detector and correspond to an integrated luminosity of 36.1 fb$^{-1}$. No statistically significant excess above the Standard Model expectation is observed; model-independent upper limits are set on the visible $\tau\nu$ production cross section. Heavy $W^{\prime}$ bosons with masses less than 3.7 TeV in the Sequential Standard Model and masses less than 2.2-3.8 TeV depending on the coupling in the non-universal G(221) model are excluded at the 95% credibility level.

8 data tables

Observed and predicted $m_{\rm T}$ distributions including SSM and NU (cot$\phi$ = 5.5) $W^{\prime}$ signals with masses of 3 TeV. Please note that in the paper figure the bin content is divided by the bin width, but this is not done in the HepData table. The table also contains each background contribution to the Standard Model expectation separately with their statistical uncertainties.

Number of expected Standard Model background events including total statistical and systematic uncertainty added in quadrature (calculated before applying the statistical fitting procedure), number of observed events, and the observed and expected 95% CL upper limits on the visible $\tau\nu$ production cross section, $\sigma_{\rm vis} = \sigma(pp \to \tau\nu +X) \cdot \mathcal{A} \cdot \varepsilon$, for $m_{\rm T}$ thresholds ranging from 250 to 1800 GeV. See HepData abstract for details on how to use this data for reinterpretation.

Observed and expected 95% CL upper limits on cross section times $\tau\nu$ branching fraction for $W^{\prime}_{\rm SSM}$.

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Search for $W' \rightarrow tb$ decays in the hadronic final state using pp collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Lett.B 781 (2018) 327-348, 2018.
Inspire Record 1650152 DOI 10.17182/hepdata.82286

A search for $W'$-boson production in the $W' \rightarrow t\bar{b} \rightarrow q\bar{q}' b\bar{b}$ decay channel is presented using 36.1 fb$^{-1}$ of 13 TeV proton-proton collision data collected by the ATLAS detector at the Large Hadron Collider in 2015 and 2016. The search is interpreted in terms of both a left-handed and a right-handed chiral $W'$ boson within the mass range 1-5 TeV. Identification of the hadronically decaying top quark is performed using jet substructure tagging techniques based on a shower deconstruction algorithm. No significant deviation from the Standard Model prediction is observed and the results are expressed as upper limits on the $W' \rightarrow t\bar{b}$ production cross-section times branching ratio as a function of the $W'$-boson mass. These limits exclude $W'$ bosons with right-handed couplings with masses below 3.0 TeV and $W'$ bosons with left-handed couplings with masses below 2.9 TeV, at the 95% confidence level.

6 data tables

Observed and expected 95% CL limits on the right-handed W'-boson cross-section times branching ratio of W' to tb decay as a function of the corresponding W'-boson mass.

Observed and expected 95% CL limits on the left-handed W'-boson cross-section times branching ratio of W' to tb decay as a function of the corresponding W'-boson mass.

Reconstructed mtb distribution in data and for the background after the fit to the data in the signal region SR1. The statistical uncertainty on data points is calculated using assymetric Poisson confidence intervals.

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Prompt and non-prompt J/$\psi$ production and nuclear modification at mid-rapidity in p-Pb collisions at ${\bf \sqrt{{\it s}_{\text{NN}}}= 5.02}$ TeV

The ALICE collaboration Acharya, Shreyasi ; Torales - Acosta, Fernando ; Adamova, Dagmar ; et al.
Eur.Phys.J.C 78 (2018) 466, 2018.
Inspire Record 1652829 DOI 10.17182/hepdata.81948

A measurement of beauty hadron production at mid-rapidity in proton-lead collisions at a nucleon-nucleon centre-of-mass energy $\sqrt{s_{\rm NN}}=5.02$ TeV is presented. The semi-inclusive decay channel of beauty hadrons into J/$\psi$ is considered, where the J/$\psi$ mesons are reconstructed in the dielectron decay channel at mid-rapidity down to transverse momenta of 1.3 GeV/$c$. The ${\rm {b\overline{b}}}$ production cross section at mid-rapidity, ${\rm d}\sigma_{\rm {b\overline{b}}}/{\rm d} y$, and the total cross section extrapolated over full phase space, $\sigma_{\rm {b\overline{b}}}$, are obtained. This measurement is combined with results on inclusive J/$\psi$ production to determine the prompt J/$\psi$ cross sections. The results in p-Pb collisions are then scaled to expectations from pp collisions at the same centre-of-mass energy to derive the nuclear modification factor $R_{\rm pPb}$, and compared to models to study possible nuclear modifications of the production induced by cold nuclear matter effects. $R_{\rm pPb}$ is found to be smaller than unity at low $p_{\rm T}$ for both J/$\psi$ coming from beauty hadron decays and prompt J/$\psi$.

12 data tables

Fraction of non-prompt J/$\psi$ in pp collisions at $\sqrt{s_{NN}}$ = 5.02 TeV for different $p_{\rm T}$ ranges, as determined with a procedure of interpolation from measurments at other energies. It is not a direct measurment.

Fraction of non-prompt J/$\psi$ in pPb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV for different $p_{\rm T}$ ranges.

Fraction of non-prompt J/$\psi$ in pPb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV for different $p_{\rm T}$ ranges.

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Comparing transverse momentum balance of b jet pairs in pp and PbPb collisions at $\sqrt{s_\mathrm{NN}} =$ 5.02 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 03 (2018) 181, 2018.
Inspire Record 1652833 DOI 10.17182/hepdata.82819

The transverse momentum balance of pairs of back-to-back b quark jets in PbPb and pp collisions recorded with the CMS detector at the LHC is reported. The center-of-mass energy in both collision systems is 5.02 TeV per nucleon pair. Compared to the pp collision baseline, b quark jets have a larger imbalance in the most central PbPb collisions, as expected from the jet quenching effect. The data are also compared to the corresponding measurement with inclusive dijets. In the most central collisions, the imbalance of b quark dijets is comparable to that of inclusive dijets.

14 data tables

Performance of double b-jet tagging, in terms of b-tagging purity and efficiency

Delta phi distributions of incluisve dijets and b-quark dijets in pp collisions

Delta phi distributions of incluisve dijets and b-quark dijets in central (0-10%) PbPb collisions

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