Measurement of dijet cross-sections in photoproduction at HERA

The H1 collaboration Adloff, C. ; Andreev, V. ; Andrieu, B. ; et al.
Eur.Phys.J.C 25 (2002) 13-23, 2002.
Inspire Record 581409 DOI 10.17182/hepdata.46764

Dijet cross sections as functions of several jet observables are measured in photoproduction using the H1 detector at HERA. The data sample comprises e^+p data with an integrated luminosity of 34.9 pb^(-1). Jets are selected using the inclusive k_T algorithm with a minimum transverse energy of 25 GeV for the leading jet. The phase space covers longitudinal proton momentum fraction x_p and photon longitudinal momentum fraction x_gamma in the ranges 0.05<x_p<0.6 and 0.1<x_gamma<1. The predictions of next-to-leading order perturbative QCD, including recent photon and proton parton densities, are found to be compatible with the data in a wide kinematical range.

10 data tables match query

Differential ep cross section for dijet production as a function of the invariant mass of the two jets.

Differential ep cross section for dijet production as a function of the average transverse energy the two jets.

Differential ep cross section for dijet production as a function of the maximum transverse energy the leading jet.

More…

Version 2
Production of D*+- mesons with dijets in deep-inelastic scattering at HERA.

The H1 collaboration Aktas, A. ; Andreev, V. ; Anthonis, T. ; et al.
Eur.Phys.J.C 51 (2007) 271-287, 2007.
Inspire Record 736052 DOI 10.17182/hepdata.45686

Inclusive D* production is measured in deep-inelastic ep scattering at HERA with the H1 detector. In addition, the production of dijets in events with a D* meson is investigated. The analysis covers values of photon virtuality 2< Q^2 <=100 GeV^2 and of inelasticity 0.05<= y <= 0.7. Differential cross sections are measured as a function of Q^2 and x and of various D* meson and jet observables. Within the experimental and theoretical uncertainties all measured cross sections are found to be adequately described by next-to-leading order (NLO) QCD calculations, based on the photon-gluon fusion process and DGLAP evolution, without the need for an additional resolved component of the photon beyond what is included at NLO. A reasonable description of the data is also achieved by a prediction based on the CCFM evolution of partons involving the k_T-unintegrated gluon distribution of the proton.

62 data tables match query

Visible cross section for inclusive D*+- production.

Visible cross section for inclusive D*+- production.

Visible cross section for inclusive D*+- production with two jets.

More…

Measurement and QCD analysis of neutral and charged current cross sections at HERA.

The H1 collaboration Adloff, C. ; Andreev, V. ; Andrieu, B. ; et al.
Eur.Phys.J.C 30 (2003) 1-32, 2003.
Inspire Record 616311 DOI 10.17182/hepdata.11903

The inclusive e^+ p single and double differential cross sections for neutral and charged current processes are measured with the H1 detector at HERA. The data were taken in 1999 and 2000 at a centre-of-mass energy of \sqrt{s} = 319 GeV and correspond to an integrated luminosity of 65.2 pb^-1. The cross sections are measured in the range of four-momentum transfer squared Q^2 between 100 and 30000 GeV^2 and Bjorken x between 0.0013 and 0.65. The neutral current analysis for the new e^+ p data and the earlier e^- p data taken in 1998 and 1999 is extended to small energies of the scattered electron and therefore to higher values of inelasticity y, allowing a determination of the longitudinal structure function F_L at high Q^2 (110 - 700 GeV^2). A new measurement of the structure function x F_3 is obtained using the new e^+ p and previously published e^\pm p neutral current cross section data at high Q^2. These data together with H1 low Q^2 precision data are further used to perform new next-to-leading order QCD analyses in the framework of the Standard Model to extract flavour separated parton distributions in the proton.

13 data tables match query

The NC cross section DSIG/DQ**2. There is an additional 1.5 PCT normalization uncertainty.

The CC cross section DSIG/DQ**2. There is an additional 1.5 PCT normalization uncertainty.

The NC cross section DSIG/DX for Q**2 > 1000 GeV**2. There is an additional 1.5 PCT normalization uncertainty.

More…

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 match query

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.

More…

Measurement of the D* Meson Production Cross Section and F_2^{ccbar}, 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 match query

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.

More…

Measurement of prompt photon cross sections in photoproduction at HERA.

The H1 collaboration Aktas, A. ; Andreev, V. ; Anthonis, T. ; et al.
Eur.Phys.J.C 38 (2005) 437-445, 2005.
Inspire Record 654175 DOI 10.17182/hepdata.46200

Results are presented on the photoproduction of isolated prompt photons, inclusively and associated with jets, in the gamma p center of mass energy range 142 < W < 266 GeV. The cross sections are measured for the transverse momentum range of the photons 5 < E_T^gamma < 10 GeV and for associated jets with E_T^jet > 4.5 GeV. They are measured differentially as a function of E_T^gamma, E_T^jet, the pseudorapidities eta^gamma and eta^jet and estimators of the momentum fractions x_gamma and x_p of the incident photon and proton carried by the constituents participating in the hard process. In order to further investigate the underlying dynamics, the angular correlation between the prompt photon and the jet in the transverse plane is studied. Predictions by perturbative QCD calculations in next to leading order are about 30% below the inclusive prompt photon data after corrections for hadronisation and multiple interactions, but are in reasonable agreement with the results for prompt photons associated with jets. Comparisons with the predictions of the event generators PYTHIA and HERWIG are also presented.

9 data tables match query

Inclusive prompt photon differential cross section as a function of ET.

Inclusive prompt photon differential cross section as a function of the pseudorapidity.

Prompt photon cross section as a function of the photon ET with an additional jet requirement.

More…

Forward pi0 meson production at HERA.

The H1 collaboration Adloff, C. ; Andreev, V. ; Andrieu, B. ; et al.
Phys.Lett.B 462 (1999) 440-452, 1999.
Inspire Record 504022 DOI 10.17182/hepdata.43918

High transverse momentum pi0-mesons have been measured with the H1 detector at HERA in deep-inelastic ep scattering events at low Bjorken-x, down to x <~ 4.10^{-5}. The measurement is performed in a region of small angles with respect to the proton remnant in the laboratory frame of reference, namely the forward region, and corresponds to central rapidity in the centre of mass system of the virtual photon and proton. This region is expected to be particularly sensitive to QCD effects in hadronic final states. Differential cross-sections for inclusive pi0-meson production are presented as a function of Bjorken-x and the four-momentum transfer Q^2, and as a function of transverse momentum and pseudorapidity. A recent numerical BFKL calculation and predictions from QCD models based on DGLAP parton evolution are compared with the data.

11 data tables match query

Axis error includes +- 5/5 contribution (Trigger efficiency).

Axis error includes +- 5/5 contribution (Trigger efficiency).

Axis error includes +- 5/5 contribution (Trigger efficiency).

More…

Inclusive D*+- meson cross sections and D*+- jet correlations in photoproduction at HERA.

The H1 collaboration Aktas, A. ; Andreev, V. ; Anthonis, T. ; et al.
Eur.Phys.J.C 50 (2007) 251-267, 2007.
Inspire Record 723915 DOI 10.17182/hepdata.45640

Differential photoproduction cross sections are measured for events containing D* mesons. The data were taken with the H1 detector at the ep collider HERA and correspond to an integrated luminosity of 51.1 pb-1. The kinematic region covers small photon virtualities Q^2 &lt; 0.01 GeV^2 and photon-proton centre-of-mass energies of 171 &lt; W_gammap &lt; 256 GeV. The details of the heavy quark production process are further investigated in events with one or two jets in addition to the D* meson. Differential cross sections for D* jet production are determined and the correlations between the D* meson and the jet(s) are studied. The results are compared with perturbative QCD predictions applying collinear- or kt -factorisation.

15 data tables match query

Integrated cross section in the visible range for inclusive D* production photoproduction.

Integrated cross section in the visible range for D*+ other jet production photoproduction.

Integrated cross section in the visible range for D* tagged dijet photoproduction.

More…

Forward jet production in deep inelastic scattering at HERA.

The H1 collaboration Aktas, A. ; Andreev, V. ; Anthonis, T. ; et al.
Eur.Phys.J.C 46 (2006) 27-42, 2006.
Inspire Record 690939 DOI 10.17182/hepdata.45860

The production of forward jets has been measured in deep inelastic ep collisions at HERA. The results are presented in terms of single differential cross sections as a function of the Bjorken scaling variable (x_{Bj}) and as triple differential cross sections d^3 \sigma / dx_{Bj} dQ^2 dp_{t,jet}^2, where Q^2 is the four momentum transfer squared and p_{t,jet}^2 is the squared transverse momentum of the forward jet. Also cross sections for events with a di-jet system in addition to the forward jet are measured as a function of the rapidity separation between the forward jet and the two additional jets. The measurements are compared with next-to-leading order QCD calculations and with the predictions of various QCD-based models.

7 data tables match query

Single differential forward jet cross section as a function of Bjorken X.

Triple differential cross section.

Triple differential cross section.

More…

Strangeness Production at low $Q^2$ in Deep-Inelastic $ep$ Scattering at HERA

The H1 collaboration Aaron, F.D. ; Alexa, C. ; Andreev, V. ; et al.
Eur.Phys.J.C 61 (2009) 185-205, 2009.
Inspire Record 810046 DOI 10.17182/hepdata.45305

The production of neutral strange hadrons is investigated using deep-inelastic scattering events measured with the H1 detector at HERA. The measurements are made in the phase space defined by the negative four-momentum transfer squared of the photon 2 &lt; Q^2 &lt; 100 GeV^2 and the inelasticity 0.1 &lt; y &lt; 0.6. The K_s and Lambda production cross sections and their ratios are determined. K_s production is compared to the production of charged particles in the same region of phase space. The Lambda - anti-Lambda asymmetry is also measured and found to be consistent with zero. Predictions of leading order Monte Carlo programs are compared to the data.

31 data tables match query

Visible cross section for the production of K0S and LAMBDA(BAR).

Ratio of strange baryon to meson production.

Ratio of K0S to charged hadron production.

More…