Date

Subject_areas

Forward production of $\Upsilon$ mesons in $pp$ collisions at $\sqrt{s}=7$ and 8TeV

The LHCb collaboration Aaij, Roel ; Adeva, Bernardo ; Adinolfi, Marco ; et al.
JHEP 1511 (2015) 103, 2015.
Inspire Record 1392456 DOI 10.17182/hepdata.249

The production of Υ mesons in pp collisions at $ \sqrt{s}=7 $ and 8 TeV is studied with the LHCb detector using data samples corresponding to an integrated luminosity of 1 fb$^{−1}$ and 2 fb$^{−1}$ respectively. The production cross-sections and ratios of cross-sections are measured as functions of the meson transverse momentum p and rapidity y, for p < 30 GeV/c and 2.0 < y < 4.5.

0 data tables match query

Forward–backward asymmetry of Drell–Yan lepton pairs in pp collisions at $\sqrt{s} = 8$ $\,\mathrm{TeV}$

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
Eur.Phys.J. C76 (2016) 325, 2016.
Inspire Record 1415949 DOI 10.17182/hepdata.73121

A measurement of the forward–backward asymmetry ${A}_{\mathrm{FB}}$ of oppositely charged lepton pairs ( $\mu \mu $ and $\mathrm{e}\mathrm{e}$ ) produced via $\mathrm{Z}/\gamma ^*$ boson exchange in pp collisions at $\sqrt{s} = 8$ $\,\mathrm{TeV}$ is presented. The data sample corresponds to an integrated luminosity of 19.7 $\,\mathrm{fb}^{-1}$ collected with the CMS detector at the LHC. The measurement of ${A}_{\mathrm{FB}}$ is performed for dilepton masses between 40 $\,\text {GeV}$ and 2 $\,\mathrm{TeV}$ and for dilepton rapidity up to 5. The ${A}_{\mathrm{FB}}$ measurements as a function of dilepton mass and rapidity are compared with the standard model predictions.

0 data tables match query

Centrality dependence of $\mathbf{\psi}$(2S) suppression in p-Pb collisions at $\mathbf{\sqrt{{\textit s}_{\rm NN}}}$ = 5.02 TeV

The ALICE collaboration Adam, Jaroslav ; Adamova, Dagmar ; Aggarwal, Madan Mohan ; et al.
JHEP 1606 (2016) 050, 2016.
Inspire Record 1426826 DOI 10.17182/hepdata.73306

The inclusive production of the ψ(2S) charmonium state was studied as a function of centrality in p-Pb collisions at the nucleon-nucleon center of mass energy $ {\sqrt{s}}_{\mathrm{NN}}=5.02 $ TeV at the CERN LHC. The measurement was performed with the ALICE detector in the center of mass rapidity ranges −4.46 < y$_{cms}$ < −2.96 and 2.03 < y$_{cms}$ < 3.53, down to zero transverse momentum, by reconstructing the ψ(2S) decay to a muon pair. The ψ(2S) production cross section σ$_{ψ(2S)}$ is presented as a function of the collision centrality, which is estimated through the energy deposited in forward rapidity calorimeters. The relative strength of nuclear effects on the ψ(2S) and on the corresponding 1S charmonium state J/ψ is then studied by means of the double ratio of cross sections [σ$_{ψ(2S)}$ /σ$_{J/ψ}$ ]$_{pPb}$ /[σ$_{ψ(2S)}$ /σ$_{J/ψ}$ ]$_{pp}$ between p-Pb and pp collisions, and by the values of the nuclear modification factors for the two charmonium states. The results show a large suppression of ψ(2S) production relative to the J/ψ at backward (negative) rapidity, corresponding to the flight direction of the Pb-nucleus, while at forward (positive) rapidity the suppressions of the two states are comparable. Finally, comparisons to results from lower energy experiments and to available theoretical models are presented.

0 data tables match query

Measurement of differential $J/\psi$ production cross sections and forward-backward ratios in p + Pb collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Rev. C92 (2015) 034904, 2015.
Inspire Record 1373747 DOI 10.17182/hepdata.77275

Measurements of differential cross sections for J/ψ production in p+Pb collisions at sNN=5.02 TeV at the CERN Large Hadron Collider with the ATLAS detector are presented. The data set used corresponds to an integrated luminosity of 28.1 nb−1. The J/ψ mesons are reconstructed in the dimuon decay channel over the transverse momentum range 8<pT<30GeV and over the center-of-mass rapidity range −2.87<y*<1.94. Prompt J/ψ are separated from J/ψ resulting from b-hadron decays through an analysis of the distance between the J/ψ decay vertex and the event primary vertex. The differential cross section for production of nonprompt J/ψ is compared to a FONLL calculation that does not include nuclear effects. Forward-backward production ratios are presented and compared to theoretical predictions. These results complement previously published results by covering a region of higher transverse momentum and more central rapidity. They thus constrain the kinematic dependence of nuclear modifications of charmonium and b-quark production in p+Pb collisions.

0 data tables match query

Measurement of the forward-backward asymmetry of $\Lambda$ and $\bar{\Lambda}$ production in $p \bar{p}$ collisions

The D0 collaboration Abazov, Victor Mukhamedovich ; Abbott, Braden Keim ; Acharya, Bannanje Sripath ; et al.
Phys.Rev. D93 (2016) 032002, 2016.
Inspire Record 1404885 DOI 10.17182/hepdata.76972

We study $\Lambda$ and $\bar{\Lambda}$ production asymmetries in $p \bar{p} \rightarrow \Lambda (\bar{\Lambda}) X$, $p \bar{p} \rightarrow J/\psi \Lambda (\bar{\Lambda}) X$, and $p \bar{p} \rightarrow \mu^\pm \Lambda (\bar{\Lambda}) X$ events recorded by the D0 detector at the Fermilab Tevatron collider at $\sqrt{s} = 1.96$ TeV. We find an excess of $\Lambda$'s ($\bar{\Lambda}$'s) produced in the proton (antiproton) direction. This forward-backward asymmetry is measured as a function of rapidity. We confirm that the $\bar{\Lambda}/\Lambda$ production ratio, measured by several experiments with various targets and a wide range of energies, is a universal function of "rapidity loss", i.e., the rapidity difference of the beam proton and the lambda.

0 data tables match query

Measurement of the $W+b$-jet and $W+c$-jet differential production cross sections in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV

The D0 collaboration Abazov, Victor Mukhamedovich ; Abbott, Braden Keim ; Acharya, Bannanje Sripath ; et al.
Phys.Lett. B743 (2015) 6-14, 2015.
Inspire Record 1334689 DOI 10.17182/hepdata.73191

We present a measurement of the cross sections for the associated production of a $W$ boson with at least one heavy quark jet, $b$ or $c$, in proton-antiproton collisions. Data corresponding to an integrated luminosity of 8.7 fb$^{-1}$ recorded with the D0 detector at the Fermilab Tevatron \ppbar Collider at $\sqrt{s}=1.96$ TeV are used to measure the cross sections differentially as a function of the jet transverse momenta in the range 20 to 150 GeV. These results are compared to calculations of perturbative QCD theory as well as predictions from Monte Carlo generators.

0 data tables match query

Production of associated Y and open charm hadrons in pp collisions at $ \sqrt{s}=7 $ and 8 TeV via double parton scattering

The LHCb collaboration Aaij, Roel ; Abellán Beteta, Carlos ; Adeva, Bernardo ; et al.
JHEP 1607 (2016) 052, 2016.
Inspire Record 1399056 DOI 10.17182/hepdata.73583

Associated production of bottomonia and open charm hadrons in pp collisions at $ \sqrt{s}=7 $ and 8 TeV is observed using data corresponding to an integrated luminosity of 3 fb$^{−1}$ accumulated with the LHCb detector. The observation of five combinations, Y(1S)D$^{0}$, Y(2S)D$^{0}$, Y(1S)D$^{+}$, Y(2S)D$^{+}$ and Y(1S)D$_{s}^{+}$ , is reported. Production crosssections are measured for Y(1S)D$^{0}$ and Y(1S)D$^{+}$ pairs in the forward region. The measured cross-sections and the differential distributions indicate the dominance of double parton scattering as the main production mechanism.

0 data tables match query

Measurement of the t-tbar production cross section in the e-mu channel in proton-proton collisions at sqrt(s) = 7 and 8 TeV

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
JHEP 1608 (2016) 029, 2016.
Inspire Record 1426692 DOI 10.17182/hepdata.74208

The inclusive cross section for top quark pair production is measured in proton-proton collisions at $ \sqrt{s}=7 $ and 8 TeV, corresponding to 5.0 and 19.7 fb$^{−1}$, respectively, with the CMS experiment at the LHC. The cross sections are measured in the electron-muon channel using a binned likelihood fit to multi-differential final state distributions related to identified b quark jets and other jets in the event. The measured cross section values are 173.6 ± 2.1(stat)$_{− 4.0}^{+ 4.5}$ (syst) ± 3.8(lumi)pb at $ \sqrt{s}=7 $ TeV, and 244.9 ± 1.4(stat)$_{− 5.5}^{+ 6.3}$ (syst) ± 6.4(lumi)pb at $ \sqrt{s}=8 $ TeV, in good agreement with QCD calculations at next-to-next-to-leading-order accuracy. The ratio of the cross sections measured at 7 and 8 TeV is determined, as well as cross sections in the fiducial regions defined by the acceptance requirements on the two charged leptons in the final state. The cross section results are used to determine the top quark pole mass via the dependence of the theoretically predicted cross section on the mass, giving a best result of 173. 8$_{− 1.8}^{+ 1.7}$ GeV. The data at $ \sqrt{s}=8 $ TeV are also used to set limits, for two neutralino mass values, on the pair production of supersymmetric partners of the top quark with masses close to the top quark mass.

0 data tables match query

Measurement of $W^{\pm}$ and $Z$-boson production cross sections in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Lett. B759 (2016) 601-621, 2016.
Inspire Record 1436497 DOI 10.17182/hepdata.73611

Measurements of the $W^{\pm} \rightarrow \ell^{\pm} \nu$ and $Z \rightarrow \ell^+ \ell^-$ production cross sections (where $\ell^{\pm}=e^{\pm},\mu^{\pm}$) in proton-proton collisions at $\sqrt{s}=13$ TeV are presented using data recorded by the ATLAS experiment at the Large Hadron Collider, corresponding to a total integrated luminosity of 81 pb$^{-1}$ The total inclusive $W^{\pm}$-boson production cross sections times the single-lepton-flavour branching ratios are $\sigma_{W^+}^{tot}= 11.83 \pm 0.02 (stat) \pm 0.32 (sys) \pm 0.25 (lumi)$ nb and $\sigma_{W^-}^{tot} = 8.79 \pm 0.02 (stat) \pm 0.24 (sys) \pm 0.18 (lumi)$ nb for $W^+$ and $W^-$, respectively. The total inclusive $Z$-boson production cross section times leptonic branching ratio, within the invariant mass window $66 < m_{\ell\ell} < 116$ GeV, is $\sigma_{Z}^{tot} = 1.981 \pm 0.007 (stat) \pm 0.038 (sys) \pm 0.042 (lumi)$ nb. The $W^+$, $W^-$, and $Z$-boson production cross sections and cross-section ratios within a fiducial region defined by the detector acceptance are also measured. The cross-section ratios benefit from significant cancellation of experimental uncertainties, resulting in $\sigma_{W^+}^{fid}/\sigma_{W^-}^{fid} = 1.295 \pm 0.003 (stat) \pm 0.010 (sys)$ and $\sigma_{W^{\pm}}^{fid}/\sigma_{Z}^{fid} = 10.31 \pm 0.04 (stat) \pm 0.20 (sys)$. Theoretical predictions, based on calculations accurate to next-to-next-to-leading order for quantum chromodynamics and to next-to-leading order for electroweak processes and which employ different parton distribution function sets, are compared to these measurements.

0 data tables match query

Search for new resonances in events with one lepton and missing transverse momentum in $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Lett. B762 (2016) 334-352, 2016.
Inspire Record 1469070 DOI 10.17182/hepdata.75363

A search for W′ bosons in events with one lepton (electron or muon) and missing transverse momentum is presented. The search uses 3.2 fb −1 of pp collision data collected at s=13 TeV by the ATLAS experiment at the LHC in 2015. The transverse mass distribution is examined and no significant excess of events above the level expected from Standard Model processes is observed. Upper limits on the W′ boson cross-section times branching ratio to leptons are set as a function of the W′ mass. Within the Sequential Standard Model W′ masses below 4.07 TeV are excluded at the 95% confidence level. This extends the limit set using LHC data at s=8 TeV by around 800 GeV.

0 data tables match query

Search for a Higgs boson decaying into $\gamma^* \gamma \to \ell \ell \gamma$ with low dilepton mass in pp collisions at $\sqrt s = $ 8 TeV

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
Phys.Lett. B753 (2016) 341-362, 2016.
Inspire Record 1382587 DOI 10.17182/hepdata.73712

A search is described for a Higgs boson decaying into two photons, one of which has an internal conversion to a muon or an electron pair ( ℓℓγ ). The analysis is performed using proton–proton collision data recorded with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 fb −1 . The events selected have an opposite-sign muon or electron pair and a high transverse momentum photon. No excess above background has been found in the three-body invariant mass range 120<mℓℓγ<150 GeV , and limits have been derived for the Higgs boson production cross section times branching fraction for the decay H→γ⁎γ→ℓℓγ , where the dilepton invariant mass is less than 20 GeV. For a Higgs boson with mH=125 GeV , a 95% confidence level (CL) exclusion observed (expected) limit is 6.7 ( 5.9−1.8+2.8 ) times the standard model prediction. Additionally, an upper limit at 95% CL on the branching fraction of H→(J/ψ)γ for the 125 GeV Higgs boson is set at 1.5×10−3 .

0 data tables match query

Evidence for exclusive $\gamma\gamma \to W^+ W^-$ production and constraints on anomalous quartic gauge couplings in $pp$ collisions at $ \sqrt{s}=7 $ and 8 TeV

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
JHEP 1608 (2016) 119, 2016.
Inspire Record 1448100 DOI 10.17182/hepdata.74707

A search for exclusive or quasi-exclusive γγ → W$^{+}$ W$^{−}$ production, via pp → p$^{(*)}$ W$^{+}$ W$^{−}$ p$^{(*)}$ → p$^{(*)}$ μ$^{±}$e$^{∓}$ p$^{(*)}$ at $ \sqrt{s}=8 $ TeV, is reported using data corresponding to an integrated luminosity of 19.7 fb$^{−1}$. Events are selected by requiring the presence of an electron-muon pair with large transverse momentum p$_{T}$(μ$^{±}$e$^{∓}$) > 30 GeV, and no associated charged particles detected from the same vertex. The 8 TeV results are combined with the previous 7 TeV results (obtained for 5.05 fb$^{−1}$ of data). In the signal region, 13 (2) events are observed over an expected background of 3.9 ± 0.6 (0.84 ± 0.15) events for 8 (7) TeV, resulting in a combined excess of 3.4σ over the background-only hypothesis. The observed yields and kinematic distributions are compatible with the standard model prediction for exclusive and quasi-exclusive γγ → W$^{+}$ W$^{−}$ production. Upper limits on the anomalous quartic gauge coupling operators a$_{0,C}^{W}$ (dimension-6) and f$_{M0,1,2,3}$ (dimension-8), the most stringent to date, are derived from the measured dilepton transverse momentum spectrum.

0 data tables match query