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Transverse momentum, rapidity, and centrality dependence of inclusive charged-particle production in $\sqrt{s_{NN}}=5.02$ TeV p+Pb collisions measured by the ATLAS experiment

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Lett.B 763 (2016) 313-336, 2016.
Inspire Record 1463284 DOI 10.17182/hepdata.75256

Measurements of the per-event charged-particle yield as a function of the charged-particle transverse momentum and rapidity are performed using $p+$Pb collision data collected by the ATLAS experiment at the LHC at a centre-of-mass energy of $\sqrt{s_{NN}}=5.02$ TeV. Charged particles are reconstructed over pseudorapidity $|\eta|<2.3$ and transverse momentum between $0.1$ GeV and $22$ GeV in a dataset corresponding to an integrated luminosity of $1$ $\mu b^{-1}$. The results are presented in the form of charged-particle nuclear modification factors, where the $p+$Pb charged-particle multiplicities are compared between central and peripheral $p+$Pb collisions as well as to charged-particle cross sections measured in pp collisions. The $p+$Pb collision centrality is characterized by the total transverse energy measured in $-4.9<\eta<-3.1$, which is in the direction of the outgoing lead beam. Three different estimations of the number of nucleons participating in the $p+$Pb collision are carried out using the Glauber model and two Glauber-Gribov colour-fluctuation extensions to the Glauber model. The values of the nuclear modification factors are found to vary significantly as a function of rapidity and transverse momentum. A broad peak is observed for all centralities and rapidities in the nuclear modification factors for charged-particle transverse momentum values around $3$ GeV. The magnitude of the peak increases for more central collisions as well as rapidity ranges closer to the direction of the outgoing lead nucleus.

59 data tables

Invariant differential $p_{T}$ spectra of charged particles which are produced in p+Pb collisions at $\sqrt{s_{NN}} = 5.02$ TeV shown in six $\eta$ intervals, for the 0--90% centrality interval. The individual spectra are scaled by constant factors (indicated in the legend) for visibility. The statistical uncertainties are indicated with vertical lines and the systematic uncertainties are indicated with boxes, but are generally much smaller than the size of the symbols.

Invariant differential $p_{T}$ spectra of charged particles which are produced in p+Pb collisions at $\sqrt{s_{NN}} = 5.02$ TeV shown in six y* intervals, for the 0--90% centrality interval. The individual spectra are scaled by constant factors (indicated in the legend) for visibility. The statistical uncertainties are indicated with vertical lines and the systematic uncertainties are indicated with boxes, but are generally much smaller than the size of the symbols.

The invariant differential y* spectra of charged particles produced in p+Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV are shown in five centrality intervals for $p_{T}>0.1$ GeV. The statistical uncertainties are indicated with vertical lines and the systematic uncertainties are indicated with boxes.

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Measurement of Z boson Production in Pb+Pb Collisions at sqrt(s_NN)=2.76 TeV with the ATLAS Detector

The ATLAS collaboration Aad, Georges ; Abajyan, Tatevik ; Abbott, Brad ; et al.
Phys.Rev.Lett. 110 (2013) 022301, 2013.
Inspire Record 1193044 DOI 10.17182/hepdata.60336

The ATLAS experiment has observed 1995 Z boson candidates in data corresponding to 0.15 inverse nb of integrated luminosity obtained in the 2011 LHC Pb+Pb run at sqrt(s_NN)=2.76 TeV. The Z bosons are reconstructed via di-electron and di-muon decay channels, with a background contamination of less than 3%. Results from the two channels are consistent and are combined. Within the statistical and systematic uncertainties, the per-event Z boson yield is proportional to the number of binary collisions estimated by the Glauber model. The elliptic anisotropy of the azimuthal distribution of the Z boson with respect to the event plane is found to be consistent with zero.

10 data tables

The corrected per-event rapidity distribution of Z bosons over the centrality region 0-80%.

The corrected per-event transverse momentum distribution of Z bosons in the centrality region 0-5%.

The corrected per-event transverse momentum distribution of Z bosons in the centrality region 5-10%.

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Kshort and Lambda production in pp interactions at sqrt(s) = 0.9 and 7 TeV measured with the ATLAS detector at the LHC

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Rev.D 85 (2012) 012001, 2012.
Inspire Record 944826 DOI 10.17182/hepdata.58341

The production of Kshort and Lambda hadrons is studied in inelastic pp collisions at sqrt(s) = 0.9 and 7 TeV collected with the ATLAS detector at the LHC using a minimum-bias trigger. The observed distributions of transverse momentum, rapidity, and multiplicity are corrected to hadron level in a model-independent way within well defined phase-space regions. The distribution of the production ratio of Lambdabar to Lambda baryons is also measured. The results are compared with various Monte Carlo simulation models. Although most of these models agree with data to within 15% in the Kshort distributions, substantial disagreements with data are found in the Lambda distributions of transverse momentum.

16 data tables

The corrected transverse momentum distribution of KS mesons at 7000 GeV.

The corrected rapidity distribution of KS mesons at 7000 GeV.

The corrected multiplicity distribution of KS mesons at 7000 GeV.

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Search for Quark Contact Interactions in Dijet Angular Distributions in pp Collisions at sqrt(s) = 7 TeV Measured with the ATLAS Detector

The ATLAS collaboration Aad, G. ; Abbott, B. ; Abdallah, J. ; et al.
Phys.Lett.B 694 (2011) 327-345, 2011.
Inspire Record 871487 DOI 10.17182/hepdata.57022

Dijet angular distributions from the first LHC pp collisions at center-of-mass energy sqrt(s) = 7 TeV have been measured with the ATLAS detector. The dataset used for this analysis represents an integrated luminosity of 3.1 pb-1. Dijet $\chi$ distributions and centrality ratios have been measured up to dijet masses of 2.8 TeV, and found to be in good agreement with Standard Model predictions. Analysis of the $\chi$ distributions excludes quark contact interactions with a compositeness scale $\Lambda$ below 3.4 TeV, at 95% confidence level, significantly exceeding previous limits.

5 data tables

CHI distribution for mass bin 340 to 520 GeV.

CHI distribution for mass bin 520 to 800 GeV.

CHI distribution for mass bin 800 to 1200 GeV.

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A study of the energy evolution of event shape distributions and their means with the DELPHI detector at LEP.

The DELPHI collaboration Abdallah, J. ; Abreu, P. ; Adam, W. ; et al.
Eur.Phys.J.C 29 (2003) 285-312, 2003.
Inspire Record 620250 DOI 10.17182/hepdata.13029

Infrared and collinear safe event shape distributions and their mean values are determined in e+e- collisions at centre-of-mass energies between 45 and 202 GeV. A phenomenological analysis based on power correction models including hadron mass effects for both differential distributions and mean values is presented. Using power corrections, alpha_s is extracted from the mean values and shapes. In an alternative approach, renormalisation group invariance (RGI) is used as an explicit constraint, leading to a consistent description of mean values without the need for sizeable power corrections. The QCD beta-function is precisely measured using this approach. From the DELPHI data on Thrust, including data from low energy experiments, one finds beta_0 = 7.86 +/- 0.32 for the one loop coefficient of the beta-function or, assuming QCD, n_f = 4.75 +/- 0.44 for the number of active flavours. These values agree well with the QCD expectation of beta_0=7.67 and n_f=5. A direct measurement of the full logarithmic energy slope excludes light gluinos with a mass below 5 GeV.

71 data tables

1-THRUST distribution.

THRUST-MAJOR distribution.

THRUST-MINOR distribution.

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Multiplicity structure of the hadronic final state in diffractive deep-inelastic scattering at HERA.

The H1 collaboration Adloff, C. ; Anderson, M. ; Andreev, V. ; et al.
Eur.Phys.J.C 5 (1998) 439-452, 1998.
Inspire Record 469495 DOI 10.17182/hepdata.44363

The multiplicity structure of the hadronic system X produced in deep-inelastic processes at HERA of the type ep -> eXY, where Y is a hadronic system with mass M_Y< 1.6 GeV and where the squared momentum transfer at the pY vertex, t, is limited to |t|<1 GeV^2, is studied as a function of the invariant mass M_X of the system X. Results are presented on multiplicity distributions and multiplicity moments, rapidity spectra and forward-backward correlations in the centre-of-mass system of X. The data are compared to results in e+e- annihilation, fixed-target lepton-nucleon collisions, hadro-produced diffractive final states and to non-diffractive hadron-hadron collisions. The comparison suggests a production mechanism of virtual photon dissociation which involves a mixture of partonic states and a significant gluon content. The data are well described by a model, based on a QCD-Regge analysis of the diffractive structure function, which assumes a large hard gluonic component of the colourless exchange at low Q^2. A model with soft colour interactions is also successful.

10 data tables

The multiplicity moment MULT as a function of the mass of the charged hadron system in the full phase space and separately in the forward and backward hemispheres.

The multiplicity moment DISPERSION as a function of the mass of the charged hadron system in the full phase space and separately in the forward and backward hemispheres.

The multiplicity moment R2 as a function of the mass of the charged hadron system in the full phase space and separately in the forward and backward hemispheres.

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Studies of quantum chromodynamics with the ALEPH detector

The ALEPH collaboration Barate, R. ; Buskulic, D. ; Decamp, D. ; et al.
Phys.Rept. 294 (1998) 1-165, 1998.
Inspire Record 428072 DOI 10.17182/hepdata.47582

Previously published and as yet unpublished QCD results obtained with the ALEPH detector at LEP1 are presented. The unprecedented statistics allows detailed studies of both perturbative and non-perturbative aspects of strong interactions to be carried out using hadronic Z and tau decays. The studies presented include precise determinations of the strong coupling constant, tests of its flavour independence, tests of the SU(3) gauge structure of QCD, study of coherence effects, and measurements of single-particle inclusive distributions and two-particle correlations for many identified baryons and mesons.

44 data tables

Charged particle sphericity distribution.

Charged particle aplanarity distribution.

Charged particle Thrust distribution.

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Jet Fragmentation and {QCD} Models in $e^+ e^-$ Annihilation at $c$.m. Energies Between 12-{GeV} and 41.5-{GeV}

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Z.Phys.C 41 (1988) 359-373, 1988.
Inspire Record 263859 DOI 10.17182/hepdata.15531

The large amount of data accumulated by the TASSO detector at 35 GeV c.m. energy has been compared with the predictions of the latest generation of perturbative QCD+fragmentation models. By adjustment of the arbitrary parameters of these models, a very good description of the global properties of hadronic events was obtained. No one model gave the best description of all features of the data, each model being better than the others for some observables and worse in other quantities. We interpret these results in terms of the underlying QCD and hadronisation schemes. The trends of the data across the energy range 12.0≦W≦41.5 GeV are generally well reproduced by the models with the parameters optimised at 35 GeV.

11 data tables

The errors include the statistical error and that from the correction procedure.

The errors include the statistical error and that from the correction procedure.

The errors include the statistical error and that from the correction procedure.

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