Charged-particle multiplicity distributions over a wide pseudorapidity range in proton-proton collisions at $\sqrt{s}=$ 0.9, 7, and 8 TeV

The ALICE collaboration Acharya, S. ; Adamová, D. ; Adolfsson, J. ; et al.
Eur.Phys.J.C 77 (2017) 852, 2017.
Inspire Record 1614477 DOI 10.17182/hepdata.78802

We present the charged-particle multiplicity distributions over a wide pseudorapidity range ($-3.4<\eta<5.0$) for pp collisions at $\sqrt{s}=$ 0.9, 7, and 8 TeV at the LHC. Results are based on information from the Silicon Pixel Detector and the Forward Multiplicity Detector of ALICE, extending the pseudorapidity coverage of the earlier publications and the high-multiplicity reach. The measurements are compared to results from the CMS experiment and to PYTHIA, PHOJET and EPOS LHC event generators, as well as IP-Glasma calculations.

90 data tables

Multiplicity distribution in the pseudorapidity region -2.0 to 2.0 for NSD collisions at a centre-of-mass energy of 900 GeV.

Multiplicity distribution in the pseudorapidity region -2.4 to 2.4 for NSD collisions at a centre-of-mass energy of 900 GeV.

Multiplicity distribution in the pseudorapidity region -3.0 to 3.0 for NSD collisions at a centre-of-mass energy of 900 GeV.

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Inclusive Deep Inelastic Scattering at High $Q^2$ with Longitudinally Polarised Lepton Beams at HERA

The H1 collaboration Aaron, F.D. ; Alexa, C. ; Andreev, V. ; et al.
JHEP 09 (2012) 061, 2012.
Inspire Record 1120512 DOI 10.17182/hepdata.64899

Inclusive e\pmp single and double differential cross sections for neutral and charged current deep inelastic scattering processes are measured with the H1 detector at HERA. The data were taken at a centre-of-mass energy of \surds = 319GeV with a total integrated luminosity of 333.7 pb-1 shared between two lepton beam charges and two longitudinal lepton polarisation modes. The differential cross sections are measured in the range of negative fourmomentum transfer squared, Q2, between 60 and 50 000GeV2, and Bjorken x between 0.0008 and 0.65. The measurements are combined with earlier published unpolarised H1 data to improve statistical precision and used to determine the structure function xF_3^gammaZ. A measurement of the neutral current parity violating structure function F_2^gammaZ is presented for the first time. The polarisation dependence of the charged current total cross section is also measured. The new measurements are well described by a next-to-leading order QCD fit based on all published H1 inclusive cross section data which are used to extract the parton distribution functions of the proton.

61 data tables

The Neutral Current Reduced Cross Section for E- P interactions with a beam polarisation of -25.8 % for Q^2 values of 120, 150, 200, 250 and 300 GeV^2.

The Neutral Current Reduced Cross Section for E- P interactions with a beam polarisation of -25.8 % for Q^2 values of 400, 500, 650, 800 and 1000 GeV^2.

The Neutral Current Reduced Cross Section for E- P interactions with a beam polarisation of -25.8 % for Q^2 values of 1200, 1500, 2000, 3000 and 5000 GeV^2.

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Inclusive Measurement of Diffractive Deep-Inelastic Scattering at HERA

The H1 collaboration Aaron, F.D. ; Alexa, C. ; Andreev, V. ; et al.
Eur.Phys.J.C 72 (2012) 2074, 2012.
Inspire Record 1094384 DOI 10.17182/hepdata.60030

The diffractive process ep \rightarrow eXY, where Y denotes a proton or its low mass excitation with MY < 1.6 GeV, is studied with the H1 experiment at HERA. The analysis is restricted to the phase space region of the photon virtuality 3 \leq Q2 \leq 1600 GeV2, the square of the four-momentum transfer at the proton vertex |t| < 1.0 GeV2 and the longitudinal momentum fraction of the incident proton carried by the colourless exchange xIP < 0.05. Triple differential cross sections are measured as a function of xIP, Q2 and beta = x/xIP where x is the Bjorken scaling variable. These measurements are made after selecting diffractive events by demanding a large empty rapidity interval separating the final state hadronic systems X and Y . High statistics measurements covering the data taking periods 1999-2000 and 2004-2007 are combined with previously published results in order to provide a single set of diffractive cross sections from the H1 experiment using the large rapidity gap selection method. The combined data represent a factor between three and thirty increase in statistics with respect to the previously published results. The measurements are compared with predictions from NLO QCD calculations based on diffractive parton densities and from a dipole model. The proton vertex factorisation hypothesis is tested.

57 data tables

The reduced diffractive cross section multiplied by X_Pomeron at XP=0.0003 and Q^2=3.5 GeV^2 . The first (sys) error is the uncorrelated systematic error and the second is the correlated systematic error.

The reduced diffractive cross section multiplied by X_Pomeron at XP=0.0003 and Q^2=5.0 GeV^2 . The first (sys) error is the uncorrelated systematic error and the second is the correlated systematic error.

The reduced diffractive cross section multiplied by X_Pomeron at XP=0.0003 and Q^2=6.5 GeV^2 . The first (sys) error is the uncorrelated systematic error and the second is the correlated systematic error.

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Measurement of Three-Jet Differential Cross Sections $d\sigma_{3jet} / dM_{3jet}$ 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.B 704 (2011) 434-441, 2011.
Inspire Record 895662 DOI 10.17182/hepdata.58856

We present the first measurement of the inclusive three-jet differential cross section as a function of the invariant mass of the three jets with the largest transverse momenta in an event in p anti-p collisions at sqrt(s) = 1.96 TeV. The measurement is made in different rapidity regions and for different jet transverse momentum requirements and is based on a data set corresponding to an integrated luminosity of 0.7 fb^{-1} collected with the D0 detector at the Fermilab Tevatron Collider. The results are used to test the three-jet matrix elements in perturbative QCD calculations at next-to-leading order in the strong coupling constant. The data allow discrimination between parametrizations of the parton distribution functions of the proton.

5 data tables

The measured 3-jet differential cross section for |y|<0.8 and pT>40 GeV.

The measured 3-jet differential cross section for |y|<1.6 and pT>40 GeV.

The measured 3-jet differential cross section for |y|<2.4 and pT>40 GeV.

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Azimuthal decorrelations and multiple parton interactions in $\gamma$+2 jet and $\gamma$+3 jet events 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.Rev.D 83 (2011) 052008, 2011.
Inspire Record 883664 DOI 10.17182/hepdata.63845

Samples of inclusive photon+2 jet and photon+3 jet events collected by the D0 experiment with an integrated luminosity of about 1fb^-1 in ppbar collisions at sqrt{s}=1.96 TeV are used to measure cross sections as a function of the angle in the plane transverse to the beam direction between the transverse momentum (pT) of the photon+leading jet system (jets are ordered in pT) and pT of the other jet for photon+2 jet, or pT sum of the two other jets for photon+3 jet events. The results are compared to different models of multiple parton interactions (MPI) in the PYTHIA and SHERPA Monte Carlo (MC) generators. The data indicate a contribution from events with double parton (DP) interactions and are well described by predictions provided by the PYTHIA MPI models with pT-ordered showers and by SHERPA with the default MPI model. The photon+2 jet data are also used to determine the fraction of events with DP interactions as a function of the azimuthal angle and as a function of the second jet pT.

4 data tables

The normalised differential cross section of the azmiuthal decorrelation variable DELTA for the GAMMA+3JET sample for the PT of the second jet in the range 15 TO 30 GeV.

The normalised differential cross section of the azmiuthal decorrelation variable DELTA for the GAMMA+2JET sample for the PT of the second jet in the range 15 TO 20 GeV.

The normalised differential cross section of the azmiuthal decorrelation variable DELTA for the GAMMA+2JET sample for the PT of the second jet in the range 20 TO 25 GeV.

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Measurement of the inclusive isolated prompt photon cross section in $pp$ collisions at $\sqrt{s}=7$ TeV with the ATLAS detector

The ATLAS collaboration Aad, G. ; Abbott, B. ; Abdallah, J. ; et al.
Phys.Rev.D 83 (2011) 052005, 2011.
Inspire Record 882463 DOI 10.17182/hepdata.57465

A measurement of the cross section for the inclusive production of isolated prompt photons in pp collisions at a centre-of-mass energy sqrt(s) = 7TeV is presented. The measurement covers the pseudorapidity ranges |eta|<1.37 and 1.52<|eta|<1.81 in the transverse energy range 15 < E_T <100 GeV. The results are based on an integrated luminosity of 880 nb-1, collected with the ATLAS detector at the Large Hadron Collider. Photon candidates are identified by combining information from the calorimeters and from the inner tracker. Residual background in the selected sample is estimated from data based on the observed distribution of the transverse isolation energy in a narrow cone around the photon candidate. The results are compared to predictions from next-to-leading order perturbative QCD calculations.

3 data tables

The measured prompt photon cross section as a function of transverse energy for the |pseudorapidity| range < 0.6.

The measured prompt photon cross section as a function of transverse energy for the |pseudorapidity| range 0.6 to 1.37.

The measured prompt photon cross section as a function of transverse energy for the |pseudorapidity| range 1.52 to 1.81.


Measurement of the $W \to \ell\nu$ and $Z/\gamma^* \to \ell\ell$ Production Cross Sections in Proton-Proton Collisions at $\sqrt{s} = 7$ TeV with the ATLAS Detector

The ATLAS collaboration Aad, G. ; Abbott, B. ; Abdallah, J. ; et al.
JHEP 12 (2010) 060, 2010.
Inspire Record 872570 DOI 10.17182/hepdata.56744

First measurements of the W -> lnu and Z/gamma* -> ll (l = e, mu) production cross sections in proton-proton collisions at sqrt(s) = 7 TeV are presented using data recorded by the ATLAS experiment at the LHC. The results are based on 2250 W -> lnu and 179 Z/gamma* -> ll candidate events selected from a data set corresponding to an integrated luminosity of approximately 320 nb-1. The measured total W and Z/gamma*-boson production cross sections times the respective leptonic branching ratios for the combined electron and muon channels are $\stotW$ * BR(W -> lnu) = 9.96 +- 0.23(stat) +- 0.50(syst) +- 1.10(lumi) nb and $\stotZg$ * BR(Z/gamma* -> ll) = 0.82 +- 0.06(stat) +- 0.05(syst) +- 0.09(lumi) nb (within the invariant mass window 66 < m_ll < 116 GeV). The W/Z cross-section ratio is measured to be 11.7 +- 0.9(stat) +- 0.4(syst). In addition, measurements of the W+ and W- production cross sections and of the lepton charge asymmetry are reported. Theoretical predictions based on NNLO QCD calculations are found to agree with the measurements.

35 data tables

Measured fiducial cross section times leptonic branching ratio for W+ production in the W+ -> e+ nu final state.

Measured fiducial cross section times leptonic branching ratio for W- production in the W- -> e- nubar final state.

Measured fiducial cross section times leptonic branching ratio for W+/- production in the combined W+ -> e+ nu and W- -> e- nubar final state.

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Precise Study of the $Z/\gamma^*$ Boson Transverse Momentum Distribution in $p\bar{p}$ Collisions using a Novel Technique

The D0 collaboration Abazov, Victor Mukhamedovich ; Abbott, Braden Keim ; Abolins, Maris A. ; et al.
Phys.Rev.Lett. 106 (2011) 122001, 2011.
Inspire Record 871787 DOI 10.17182/hepdata.56732

Using 7.3 pb-1 of ppbar collisions collected by the D0 detector at the Fermilab Tevatron, we measure the distribution of the variable \phistar, which probes the same physical effects as the Z/gamma* boson transverse momentum, but is less susceptible to the effects of experimental resolution and efficiency. A QCD prediction is found to describe the general features of the \phistar distribution, but is unable to describe its detailed shape or dependence on boson rapidity. A prediction that includes a broadening of transverse momentum for small values of the parton momentum fraction is strongly disfavored.

2 data tables

The measured PHI* distributions for the dielectron events corrected back to the particle level. The distributions are normalised to unity inidividually for each abs(yrap) bin and channel.

The measured PHI* distributions for the dimuon events corrected back to the particle level. The distributions are normalised to unity inidividually for each abs(yrap) bin and channel.


Measurement of Inclusive Jet and Dijet Cross Sections in Proton-Proton Collisions at 7 TeV Centre-of-Mass Energy with the ATLAS Detector

The ATLAS collaboration Aad, G. ; Abbott, B. ; Abdallah, J. ; et al.
Eur.Phys.J.C 71 (2011) 1512, 2011.
Inspire Record 871366 DOI 10.17182/hepdata.56004

Jet cross sections have been measured for the first time in proton-proton collisions at a centre-of-mass energy of 7 TeV using the ATLAS detector. The measurement uses an integrated luminosity of 17 nb-1 recorded at the Large Hadron Collider. The anti-kt algorithm is used to identify jets, with two jet resolution parameters, R = 0.4 and 0.6. The dominant uncertainty comes from the jet energy scale, which is determined to within 7% for central jets above 60 GeV transverse momentum. Inclusive single-jet differential cross sections are presented as functions of jet transverse momentum and rapidity. Dijet cross sections are presented as functions of dijet mass and the angular variable $\chi$. The results are compared to expectations based on next-to-leading-order QCD, which agree with the data, providing a validation of the theory in a new kinematic regime.

26 data tables

Inclusive jet double-differential cross sections in the |rapidity| range 0 to 0.3, using a jet resolution R value of 0.4. The three (sys) errors are respectively, the Absolute JES, the Unfolding and the Luminosity uncertainties.

Inclusive jet double-differential cross sections in the |rapidity| range 0.3 to 0.8, using a jet resolution R value of 0.4. The three (sys) errors are respectively, the Absolute JES, the Unfolding and the Luminosity uncertainties.

Inclusive jet double-differential cross sections in the |rapidity| range 0.8 to 1.2, using a jet resolution R value of 0.4. The three (sys) errors are respectively, the Absolute JES, the Unfolding and the Luminosity uncertainties.

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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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Search for New Particles in Two-Jet Final States in 7 TeV Proton-Proton Collisions with the ATLAS Detector at the LHC

The ATLAS collaboration Aad, G. ; Abbott, B. ; Abdallah, J. ; et al.
Phys.Rev.Lett. 105 (2010) 161801, 2010.
Inspire Record 865423 DOI 10.17182/hepdata.57036

A search for new heavy particles manifested as resonances in two-jet final states is presented. The data were produced in 7 TeV proton-proton collisions by the Large Hadron Collider (LHC) and correspond to an integrated luminosity of 315 nb^-1 collected by the ATLAS detector. No resonances were observed. Upper limits were set on the product of cross section and signal acceptance for excited-quark (q*) production as a function of q* mass. These exclude at the 95% CL the q* mass interval 0.30 < mq* < 1.26 TeV, extending the reach of previous experiments.

2 data tables

The dijet mass distribution (NUMBER OF EVENTS).

95 PCT CL upper limit of the cross section x acceptance.


Measurement of the Normalized $Z/\gamma^* -> \mu^+\mu^-$ Transverse Momentum Distribution in $p\bar{p}$ Collisions at $\sqrt{s}=1.96$ TeV

The D0 collaboration Abazov, Victor Mukhamedovich ; Abbott, Braden Keim ; Abolins, Maris A. ; et al.
Phys.Lett.B 693 (2010) 522-530, 2010.
Inspire Record 856972 DOI 10.17182/hepdata.55457

We present a new measurement of the Z/gamma* transverse momentum distribution in the range 0 - 330GeV, in proton-antiproton collisions at sqrt{s}=1.96 TeV. The measurement uses 0.97 fb-1 of integrated luminosity recorded by the D0 experiment and is the first using the Z/gamma*->mu+mu- + X channel at this center-of-mass energy. This is also the first measurement of the Z/gamma* transverse momentum distribution that presents the result at the level of particles entering the detector, minimizing dependence on theoretical models. As any momentum of the Z/gamma* in the plane transverse to the incoming beams must be balanced by some recoiling system, primarily the result of QCD radiation in the initial state, this variable is an excellent probe of the underlying process. Tests of the predictions of QCD calculations and current event generators show they have varied success in describing the data. Using this measurement as an input to theoretical predictions will allow for a better description of hadron collider data and hence it will increase experimental sensitivity to rare signals.

2 data tables

Normalized differential cross section.

Absolute differential cross section produced by multiplying by the measuredtotal cross section (118 pb).


Charged-particle multiplicities in $pp$ interactions at $\sqrt{s}=900$ GeV measured with the ATLAS detector at the LHC

The ATLAS collaboration Aad, G. ; Abat, E. ; Abbott, B. ; et al.
Phys.Lett.B 688 (2010) 21-42, 2010.
Inspire Record 849050 DOI 10.17182/hepdata.54850

The first measurements from proton-proton collisions recorded with the ATLAS detector at the LHC are presented. Data were collected in December 2009 using a minimum-bias trigger during collisions at a centre-of-mass energy of 900 GeV. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity, and the relationship between mean transverse momentum and charged-particle multiplicity are measured for events with at least one charged particle in the kinematic range |eta|<2.5 and pT>500 MeV. The measurements are compared to Monte Carlo models of proton-proton collisions and to results from other experiments at the same centre-of-mass energy. The charged-particle multiplicity per event and unit of pseudorapidity at eta = 0 is measured to be 1.333 +/- 0.003 (stat.) +/- 0.040 (syst.), which is 5-15% higher than the Monte Carlo models predict.

5 data tables

Average value of charged particle multiplicity per event and unit of pseudorapidity in the pseudorapidity range from -0.2 to 0.2.

Charged particle multiplicity as a function of pseudorapidity.

Charged particle multiplicity as a function of transverse momentum.

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Measurement of the Dijet Invariant Mass Cross Section in $p\bar{p}$ Collisions at $\sqrt{s}=1.96$ TeV

The D0 collaboration Abazov, V.M. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Lett.B 693 (2010) 531-538, 2010.
Inspire Record 846483 DOI 10.17182/hepdata.54666

The inclusive dijet production double differential cross section as a function of the dijet invariant mass and of the largest absolute rapidity of the two jets with the largest transverse momentum in an event is measured in proton anti-proton collisions at sqrt{s} = 1.96 TeV using 0.7 fb^{-1} integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. The measurement is performed in six rapidity regions up to a maximum rapidity of 2.4. Next-to-leading order perturbative QCD predictions are found to be in agreement with the data.

6 data tables

Dijet double differential cross section for the absolute rapidity region 0.0 to 0.4.

Dijet double differential cross section for the absolute rapidity region 0.4 to 0.8.

Dijet double differential cross section for the absolute rapidity region 0.8 to 1.2.

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Measurement of Direct Photon Pair Production Cross Sections in $p\bar{p}$ Collisions at $\sqrt{s}=1.96$ TeV

The D0 collaboration Abazov, V.M. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Lett.B 690 (2010) 108-117, 2010.
Inspire Record 846997 DOI 10.17182/hepdata.54534

We present a measurement of direct photon pair production cross sections using 4.2 fb-1 of data collected with the D0 detector at the Fermilab Tevatron proton-antiproton Collider. We measure single differential cross sections as a function of the diphoton mass, the transverse momentum of the diphoton system, the azimuthal angle between the photons, and the polar scattering angle of the photons, as well as the double differential cross sections considering the last three kinematic variables in three diphoton mass bins. The results are compared with different perturbative QCD predictions and event generators.

13 data tables

Single differential cross section DSIG/DM.

Single differential cross section DSIG/DPT.

Single differential cross section DSIG/DPHI.

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Jet Production in ep Collisions at Low Q**2 and Determination of alpha(s)

The H1 collaboration Aaron, F.D. ; Aldaya Martin, M. ; Alexa, C. ; et al.
Eur.Phys.J.C 67 (2010) 1-24, 2010.
Inspire Record 838435 DOI 10.17182/hepdata.31170

The production of jets is studied in deep-inelastic e+p scattering at low negative four momentum transfer squared 5<Q^2<100 GeV^2 and at inelasticity 0.2<y<0.7 using data recorded by the H1 detector at HERA in the years 1999 and 2000, corresponding to an integrated luminosity of 43.5 pb^-1. Inclusive jet, 2-jet and 3-jet cross sections as well as the ratio of 3-jet to 2-jet cross sections are measured as a function of Q^2 and jet transverse momentum. The 2-jet cross section is also measured as a function of the proton momentum fraction xi. The measurements are well described by perturbative quantum chromodynamics at next-to-leading order corrected for hadronisation effects and are subsequently used to extract the strong coupling alpha_s.

13 data tables

Inclusive Jet Cross Section ${\rm\frac{d\sigma_{jet}}{dQ^2}}$.

2-Jet Cross Section ${\rm\frac{d\sigma_{2-jet}}{dQ^2}}$.

3-Jet Cross Section ${\rm\frac{d\sigma_{3-jet}}{dQ^2}}$.

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Measurement of Leading Neutron Production in Deep-Inelastic Scattering at HERA

The H1 collaboration Aaron, F.D. ; Alexa, C. ; Alimujiang, K. ; et al.
Eur.Phys.J.C 68 (2010) 381-399, 2010.
Inspire Record 841764 DOI 10.17182/hepdata.56005

The production of leading neutrons, where the neutron carries a large fraction x_L of the incoming proton's longitudinal momentum, is studied in deep-inelastic positron-proton scattering at HERA. The data were taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of 122 pb^{-1}. The semi-inclusive cross section is measured in the phase space defined by the photon virtuality 6 < Q^2 < 100 GeV^2, Bjorken scaling variable 1.5x10^{-4} < x < 3x10^{-2}, longitudinal momentum fraction 0.32 < x_L < 0.95 and neutron transverse momentum p_T < 0.2 GeV. The leading neutron structure function, F_2^{LN(3)}(Q^2,x,x_L), and the fraction of deep-inelastic scattering events containing a leading neutron are studied as a function of Q^2, x and x_L. Assuming that the pion exchange mechanism dominates leading neutron production, the data provide constraints on the shape of the pion structure function.

30 data tables

Differential cross section of leading neutron production.

The semi-inclusive leading neutron structure function for Q**2.

The semi-inclusive leading neutron structure function for Q**2.

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Prompt Photons in Photoproduction at HERA

The H1 collaboration Aaron, F.D. ; Aldaya Martin, M. ; Alexa, C. ; et al.
Eur.Phys.J.C 66 (2010) 17-33, 2010.
Inspire Record 835534 DOI 10.17182/hepdata.56856

The production of prompt photons is measured in the photoproduction regime of electron-proton scattering at HERA. The analysis is based on a data sample corresponding to a total integrated luminosity of 340 pb^-1 collected by the H1 experiment. Cross sections are measured for photons with transverse momentum and pseudorapidity in the range 6 < Et < 15 GeV and -1.0 < eta < 2.4, respectively. Cross sections for events with an additional jet are measured as a function of the transverse energy and pseudorapidity of the jet, and as a function of the fractional momenta x_gamma and x_p carried by the partons entering the hard scattering process. The correlation between the photon and the jet is also studied. The results are compared with QCD predictions based on the collinear and on the k_T factorisation approaches.

17 data tables

Measured inclusive prompt photon cross section in the defined phase space.

Measured prompt photon plus jet cross section in the defined phase space.

Bin averaged differential cross section as a function of ET in the defined phase space.

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Dependence of the $t\bar{t}$ Production Cross Section on the Transverse Momentum of the Top Quark

The D0 collaboration Abazov, V.M. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Lett.B 693 (2010) 515-521, 2010.
Inspire Record 842641 DOI 10.17182/hepdata.54975

We present a measurement of the differential cross section for $t\bar{t}$ events produced in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV as a function of the transverse momentum ($p_T$) of the top quark. The selected events contain a high-$p_T$ lepton ($\ell$), four or more jets, and a large imbalance in $p_T$, and correspond to 1 fb${}^{-1}$ of integrated luminosity recorded with the D0 detector. Each event must have at least one candidate for a $b$ jet. Objects in the event are associated through a constrained kinematic fit to the $t\bar{t}\to WbW\bar{b} \to \ell\nu b q\bar{q}'\bar{b}$ process. Results from next-to-leading-order perturbative QCD calculations agree with the measured differential cross section. Comparisons are also provided to predictions from Monte Carlo event generators using QCD calculations at different levels of precision.

2 data tables

Total cross section for TOP TOPBAR production integrating over PT.

The inclusive PT spectra for TOP TOPBAR production.


Diffractive Dijet Photoproduction in ep Collisions at HERA

The H1 collaboration Aaron, F.D. ; Alexa, C. ; Andreev, V. ; et al.
Eur.Phys.J.C 70 (2010) 15-37, 2010.
Inspire Record 857109 DOI 10.17182/hepdata.61487

Measurements are presented of single and double-differential dijet cross sections in diffractive photoproduction based on a data sample with an integrated luminosity of 47 pb^-1. The events are of the type ep -> eXY, where the hadronic system X contains at least two jets and is separated by a large rapidity gap from the system Y, which consists of a leading proton or low-mass proton excitation. The dijet cross sections are compared with QCD calculations at next-to-leading order and with a Monte Carlo model based on leading order matrix elements with parton showers. The measured cross sections are smaller than those obtained from the next-to-leading order calculations by a factor of about 0.6. This suppression factor has no significant dependence on the fraction x_gamma of the photon four-momentum entering the hard subprocess. Ratios of the diffractive to the inclusive dijet cross sections are measured for the first time and are compared with Monte Carlo models.

18 data tables

Total diffractive dijet positron-proton cross section integrated over the full measured kinematic range.

Bin averaged hadron level differential cross section for diffractive dijet production as a function of X(C=GAMMA). The first systematic error is the uncorrelated and the second the correlated uncertainty.

Bin averaged hadron level differential cross section for diffractive dijet production as a function of the ET of jet 1. The first systematic error is the uncorrelated and the second the correlated uncertainty.

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Inelastic Production of J/psi Mesons in Photoproduction and Deep Inelastic Scattering at HERA

The H1 collaboration Aaron, F.D. ; Alexa, C. ; Andreev, V. ; et al.
Eur.Phys.J.C 68 (2010) 401-420, 2010.
Inspire Record 844299 DOI 10.17182/hepdata.60488

A measurement is presented of inelastic photo- and electroproduction of J/psi mesons in ep scattering at HERA. The data were recorded with the H1 detector in the period from 2004 to 2007. Single and double differential cross sections are determined and the helicity distributions of the J/psi mesons are analysed. The results are compared to theoretical predictions in the colour singlet model and in the framework of non-relativistic QCD. Calculations in the colour singlet model using a k_T factorisation ansatz are able to give a good description of the data, while colour singlet model calculations to next-to-leading order in collinear factorisation underestimate the data.

19 data tables

Measured differential photoproduction cross section as a function of the squared transverse momentum of the J/PSI.

Measured differential photoproduction cross section as a function of the elasticity of the J/PSI.

Measured photoproduction cross section as a function of the photon-proton centre of mass energy W.

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Measurement of the $t\bar{t}$ cross section using high-multiplicity jet events

The D0 collaboration Abazov, V.M. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.D 82 (2010) 032002, 2010.
Inspire Record 837547 DOI 10.17182/hepdata.52975

We present a measurement of the ttbar cross section using high-multiplicity jet events produced in ppbar collisions at sqrt{s}=1.96 TeV. These data were recorded at the Fermilab Tevatron collider with the D0 detector. Events with at least six jets, two of them identified as b jets, were selected from a 1 fb-1 data set. The measured cross section, assuming a top quark mass of 175 GeV/c^2, is 6.9 \pm 2.0 pb, in agreement with theoretical expectations.

1 data table

Measured top topbar cross section at two values of the top mass.


Diffractive Electroproduction of rho and phi Mesons at HERA

The H1 collaboration Aaron, F.D. ; Aldaya Martin, M. ; Alexa, C. ; et al.
JHEP 05 (2010) 032, 2010.
Inspire Record 835609 DOI 10.17182/hepdata.56191

Diffractive electroproduction of rho and phi mesons is measured at HERA with the H1 detector in the elastic and proton dissociative channels. The data correspond to an integrated luminosity of 51 pb^-1. About 10500 rho and 2000 phi events are analysed in the kinematic range of squared photon virtuality 2.5 &lt; Q^2 &lt; 60 GeV^2, photon-proton centre of mass energy 35 &lt; W &lt; 180 GeV and squared four-momentum transfer to the proton |t| &lt; 3 GeV^2. The total, longitudinal and transverse cross sections are measured as a function of Q^2, W and |t|. The measurements show a transition to a dominantly "hard" behaviour, typical of high gluon densities and small q\bar{q} dipoles, for Q^2 larger than 10 to 20 GeV^2. They support flavour independence of the diffractive exchange, expressed in terms of the scaling variable (Q^2 + M_V^2)/4, and proton vertex factorisation. The spin density matrix elements are measured as a function of kinematic variables. The ratio of the longitudinal to transverse cross sections, the ratio of the helicity amplitudes and their relative phases are extracted. Several of these measurements have not been performed before and bring new information on the dynamics of diffraction in a QCD framework. The measurements are discussed in the context of models using generalised parton distributions or universal dipole cross sections.

108 data tables

Q**2 dependence of the GAMMA* P elastic RHO0 meson production at mean W There is an additional overall normalization uncertainty of 3.9 PCT.

Q**2 dependence of the GAMMA* P cross section for proton dissociative RHO0 meson production at mean W There is an additional overall normalization uncertainty of 4.6 PCT.

Q**2 dependence of the GAMMA* P elastic PHI meson production at mean W There is an additional overall normalization uncertainty of 4.7 PCT.

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Measurement of the D*+- Meson Production Cross Section and F(2)**(c c-bar), at High Q**2, in ep Scattering at HERA

The H1 collaboration Aaron, F.D. ; Alexa, C. ; Alimujiang, K. ; et al.
Phys.Lett.B 686 (2010) 91-100, 2010.
Inspire Record 837434 DOI 10.17182/hepdata.55370

The inclusive production of D*(2010) mesons in deep-inelastic ep scattering is measured in the kinematic region of photon virtuality 100 &lt; Q^2 &lt; 1000 GeV^2 and inelasticity 0.02 &lt; y &lt; 0.7. Single and double differential cross sections for inclusive D* meson production are measured in the visible range defined by |eta(D*)| &lt; 1.5 and p_T(D*) > 1.5 GeV. The data were collected by the H1 experiment during the period from 2004 to 2007 and correspond to an integrated luminosity of 351 pb^{-1}. The charm contribution, F_2^{ccbar}, to the proton structure function F_2 is determined. The measurements are compared with QCD predictions.

12 data tables

Total inclusive cross section for D*+- production.

Single differential cross section DSIG/DPT for D*+- production. The DSYS errors are the uncorrelated and correlated systematicuncertainties respectively.

Single differential cross section DSIG/DETARAP for D*+- production. The DSYS errors are the uncorrelated and correlated systematicuncertainties respectively.

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Combined Measurement and QCD Analysis of the Inclusive e+- p Scattering Cross Sections at HERA

The H1 & ZEUS collaborations Aaron, F.D. ; Abramowicz, H. ; Abt, I. ; et al.
JHEP 01 (2010) 109, 2010.
Inspire Record 836107 DOI 10.17182/hepdata.58304

A combination is presented of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current unpolarised ep scattering at HERA during the period 1994-2000. The data span six orders of magnitude in negative four-momentum-transfer squared, Q^2, and in Bjorken x. The combination method used takes the correlations of systematic uncertainties into account, resulting in an improved accuracy. The combined data are the sole input in a NLO QCD analysis which determines a new set of parton distributions HERAPDF1.0 with small experimental uncertainties. This set includes an estimate of the model and parametrisation uncertainties of the fit result.

89 data tables

Combined reduced cross section data and F2 for Neutral Current E+ P scattering at Q**2=0.045 GeV**2.

Combined reduced cross section data and F2 for Neutral Current E+ P scattering at Q**2=0.065 GeV**2.

Combined reduced cross section data and F2 for Neutral Current E+ P scattering at Q**2=0.085 GeV**2.