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

Visible cross section for inclusive D*+- production.

Visible cross section for inclusive D*+- production.

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

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Exclusive $\rho^0$ Meson Photoproduction with a Leading Neutron at HERA

The H1 collaboration Andreev, V. ; Baghdasaryan, A. ; Begzsuren, K. ; et al.
Eur.Phys.J.C 76 (2016) 41, 2016.
Inspire Record 1387751 DOI 10.17182/hepdata.74219

A first measurement is presented of exclusive photoproduction of $\rho^0$ mesons associated with leading neutrons at HERA. The data were taken with the H1 detector in the years $2006$ and $2007$ at a centre-of-mass energy of $\sqrt{s}=319$ GeV and correspond to an integrated luminosity of $1.16$ pb$^{-1}$. The $\rho^0$ mesons with transverse momenta $p_T<1$ GeV are reconstructed from their decays to charged pions, while leading neutrons carrying a large fraction of the incoming proton momentum, $x_L>0.35$, are detected in the Forward Neutron Calorimeter. The phase space of the measurement is defined by the photon virtuality $Q^2 < 2$ GeV$^2$, the total energy of the photon-proton system $20 < W_{\gamma p} < 100$ GeV and the polar angle of the leading neutron $\theta_n < 0.75$ mrad. The cross section of the reaction $\gamma p \to \rho^0 n \pi^+$ is measured as a function of several variables. The data are interpreted in terms of a double peripheral process, involving pion exchange at the proton vertex followed by elastic photoproduction of a $\rho^0$ meson on the virtual pion. In the framework of one-pion-exchange dominance the elastic cross section of photon-pion scattering, $\sigma^{\rm el}(\gamma\pi^+ \to \rho^0\pi^+)$, is extracted. The value of this cross section indicates significant absorptive corrections for the exclusive reaction $\gamma p\to\rho^0 n \pi^+$.

11 data tables

The $\gamma p$ cross section integrated in the domain $0.35 < x_L < 0.95$ and $-t^\prime < 1$~GeV$^2$ and averaged over the energy range $20 < W_{\gamma p} < 100$ GeV for two intervals of leading neutron transverse momentum.

Differential photoproduction cross sections ${\rm d}\sigma_{\gamma p}/{\rm d}x_L$ for the exclusive process $\gamma p \to \rho^0 n \pi^+$ in two regions of neutron transverse momentum and $20 < W_{\gamma p} < 100$ GeV. The statistical, uncorrelated and correlated systematic uncertainties, $\delta_{stat}$, $\delta_{sys}^{unc}$ and $\delta_{sys}^{cor}$ respectively, are given, which does not include the global normalisation error of $4.4\%$.

Double differential photoproduction cross sections ${\rm d^2}\sigma_{\gamma p}/{\rm d}x_L{\rm d}p_{T,n}^2$ in the range $20 < W_{\gamma p} < 100$ GeV. The statistical, uncorrelated and correlated systematic uncertainties, $\delta_{stat}$, $\delta_{sys}^{unc}$ and $\delta_{sys}^{cor}$ respectively, are given, which does not include the global normalisation error of $4.4\%$.

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Multi - Hadronic Events at E(c.m.) = 29-GeV and Predictions of QCD Models from E(c.m.) = 29-GeV to E(c.m.) = 93-GeV

Petersen, A. ; Abrams, G.S. ; Adolphsen, Chris ; et al.
Phys.Rev.D 37 (1988) 1, 1988.
Inspire Record 246184 DOI 10.17182/hepdata.4114

Multihadronic e+e− annihilation events at a center-of-mass energy of 29 GeV have been studied with both the original (PEP 5) Mark II and the upgraded Mark II detectors. Detector-corrected distributions from global shape analyses such as aplanarity, Q2-Q1, sphericity, thrust, minor value, oblateness, and jet masses, and inclusive charged-particle distributions including x, rapidity, p⊥, and particle flow are presented. These distributions are compared with predictions from various multihadron event models which use leading-logarithmic shower evolution or QCD matrix elements at the parton level and string or cluster fragmentation for hadronization. The new generation of parton-shower models gives, on the average, a better description of the data than the previous parton-shower models. The energy behavior of these models is compared to existing e+e− data. The predictions of the models at a center-of-mass energy of 93 GeV, roughly the expected mass of the Z0, are also presented.

74 data tables

Aplanarity distribution.

QX Distribution(QX=SQRT(3)*(Q3-Q2)).

The (Q2-Q1) distribution.

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Measurement of Dijet Production in Diffractive Deep-Inelastic ep Scattering at HERA

The H1 collaboration Andreev, V. ; Baghdasaryan, A. ; Begzsuren, K. ; et al.
JHEP 03 (2015) 092, 2015.
Inspire Record 1332186 DOI 10.17182/hepdata.73124

A measurement is presented of single- and double-differential dijet cross sections in diffractive deep-inelastic $ep$ scattering at HERA using data collected by the H1 experiment corresponding to an integrated luminosity of 290 pb^{-1}. The investigated phase space is spanned by the photon virtuality in the range of 4<Q^{2}<100 GeV^{2} and by the fractional proton longitudinal momentum loss x_pom<0.03. The resulting cross sections are compared with next-to-leading order QCD predictions based on diffractive parton distribution functions and the value of the strong coupling constant is extracted.

11 data tables

Integrated cross section in the measurement phase space.

Diffractive DIS dijet cross section measured differentially as a function of $Q^2$. The global normalisation uncertainty of $7.8\%$ is not listed explicitly but is included in the total systematic uncertainty. The last two columns show the correction factors for hadronisation and QED radiation, respectively.

Diffractive DIS dijet cross section measured differentially as a function of $y$. The global normalisation uncertainty of $7.8\%$ is not listed explicitly but is included in the total systematic uncertainty. The last two column show the correction factors for hadronisation and QED radiation, respectively.

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Measurement of D^{+} and Lambda_{c}^{+} production in deep inelastic scattering at HERA

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
JHEP 11 (2010) 009, 2010.
Inspire Record 860842 DOI 10.17182/hepdata.57020

Charm production in deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 120 pb^{-1}. The hadronic decay channels D^{+} -> K^{0}_{S} pi^{+}, Lambda_{c}^{+} -> p K^{0}_{S} and Lambda_{c}^{+} -> Lambda pi^{+}, and their charge conjugates, were reconstructed. The presence of a neutral strange hadron in the final state reduces the combinatorial background and extends the measured sensitivity into the low transverse momentum region. The kinematic range is 0 < p_{T}(D^{+}, Lambda_{c}^{+}) < 10 GeV, |eta(D^{+}, Lambda_{c}^{+})| < 1.6, 1.5 < Q^{2} < 1000 GeV^{2} and 0.02 < y < 0.7. Inclusive and differential cross sections for the production of D^{+} mesons are compared to next-to-leading-order QCD predictions. The fraction of c quarks hadronising into Lambda_{c}^{+} baryons is extracted.

8 data tables

Total visible cross section for D+ production. The second systematic error is due to the uncertainty in the branching ratios for D+ to (KOS PI+).

Total visible cross section for LAMBDA/C+ production via the decay channel into (P K0S). The second systematic error reflects the uncertainty in the branching ratio to (P K0S).

Total visible cross section for LAMBDA/C+ production via the decay channel into (LAMBDA PI+). The second systematic error reflects the uncertainty in the branching ratio to (LAMBDA PI+).

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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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Measurement of beauty production in deep inelastic scattering at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Loizides, J.H. ; et al.
Phys.Lett.B 599 (2004) 173-189, 2004.
Inspire Record 650875 DOI 10.17182/hepdata.53981

The beauty production cross section for deep inelastic scattering events with at least one hard jet in the Breit frame together with a muon has been measured, for photon virtualities Q^2 > 2 GeV^2, with the ZEUS detector at HERA using integrated luminosity of 72 pb^-1. The total visible cross section is sigma_b-bbar (ep -> e jet mu X) = 40.9 +- 5.7 (stat.) +6.0 -4.4 (syst.) pb. The next-to-leading order QCD prediction lies about 2.5 standard deviations below the data. The differential cross sections are in general consistent with the NLO QCD predictions: however at low values of Q^2, Bjorken x, and muon transverse momentum, and high values of jet transverse energy and muon pseudorapidity, the prediction is about two standard deviations below the data.

6 data tables

Total visible cross section in the specified kinematic region.

Differential cross section w.r.t. Q**2.

Differential cross section w.r.t. log10(x).

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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

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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Leading proton production in deep inelastic scattering at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
JHEP 06 (2009) 074, 2009.
Inspire Record 805171 DOI 10.17182/hepdata.53754

The semi-inclusive reaction e+ p -> e+ X p was studied with the ZEUS detector at HERA using an integrated luminosity of 12.8 pb-1. The final-state proton, which was detected with the ZEUS leading proton spectrometer, carried a large fraction of the incoming proton energy, xL>0.32, and its transverse momentum squared satisfied pT^2<0.5 GeV^2/ the exchanged photon virtuality, Q^2, was greater than 3 GeV^2 and the range of the masses of the photon-proton system was 45<W<225 GeV. The leading proton production cross section and rates are presented as a function of xL, pT^2, Q^2 and the Bjorken scaling variable, x.

171 data tables

Double differential cross sections as a funtion of PT**2 for the XL range 0.32 TO 0.38. The methods S123 and S456 are the results using different stations of the silicon microstrip detectors.

Double differential cross sections as a funtion of PT**2 for the XL range 0.38 TO 0.44. The methods S123 and S456 are the results using different stations of the silicon microstrip detectors.

Double differential cross sections as a funtion of PT**2 for the XL range 0.44 TO 0.50. The methods S123 and S456 are the results using different stations of the silicon microstrip detectors.

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Measurement of D+- and D0 production in deep inelastic scattering using a lifetime tag at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Eur.Phys.J.C 63 (2009) 171-188, 2009.
Inspire Record 810112 DOI 10.17182/hepdata.51856

The production of D+- and D0 mesons has been measured with the ZEUS detector at HERA using an integrated luminosity of 133.6 pb-1. The measurements cover the kinematic range 5 < Q^2 < 1000 GeV^2, 0.02 < y < 0.7, 1.5 < p_T^D < 15 GeV and eta^D < 1.6. Combinatorial background to the D meson signals is reduced by using the ZEUS microvertex detector to reconstruct displaced secondary vertices. Production cross sections are compared with the predictions of next-to-leading-order QCD which is found to describe the data well. Measurements are extrapolated to the full kinematic phase space in order to obtain the open-charm contribution, F2^ccbar, to the proton structure function, F2.

21 data tables

Production cross section for (D+ + D-) mesons.

Production cross section for (D0 + DBAR0) mesons not originating from D*+- decays.

Measured D+- cross section as a function of Q**2.

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Beauty photoproduction using decays into electrons at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Phys.Rev.D 78 (2008) 072001, 2008.
Inspire Record 786814 DOI 10.17182/hepdata.45317

Photoproduction of beauty quarks in events with two jets and an electron associated with one of the jets has been studied with the ZEUS detector at HERA using an integrated luminosity of 120pb^-1. The fractions of events containing b quarks, and also of events containing c quarks, were extracted from a likelihood fit using variables sensitive to electron identification as well as to semileptonic decays. Total and differential cross sections for beauty and charm production were measured and compared with next-to-leading-order QCD calculations and Monte Carlo models.

7 data tables

Total cross sections for electrons from beauty and charm quarks.

Differential electron cross sections as a function of PT and ETARAP from beauty and charm quarks.

Differential electron cross sections as a function of PT and ETARAP from beauty and charm quarks.

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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

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.

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Three- and Four-jet Production at Low x at HERA

The H1 collaboration Aaron, F.D. ; Aktas, A. ; Alexa, C. ; et al.
Eur.Phys.J.C 54 (2008) 389-409, 2008.
Inspire Record 767896 DOI 10.17182/hepdata.45429

Three- and four-jet production is measured in deep-inelastic $ep$ scattering at low $x$ and $Q^2$ with the H1 detector using an integrated luminosity of $44{.}2 {\rm pb}^{-1}$. Several phase space regions are selected for the three-jet analysis in order to study the underlying parton dynamics from global topologies to the more restrictive regions of forward jets close to the proton direction. The measurements of cross sections for events with at least three jets are compared to fixed order QCD predictions of ${\mathcal{O}}(\alpha_{\rm s}^2)$ and ${\mathcal{O}}(\alpha_{\rm s}^3) $ and with Monte Carlo simulation programs where higher order effects are approximated by parton showers. A good overall description is provided by the ${\mathcal{O}}(\alpha_{\rm s}^3) $ calculation. Too few events are predicted at the lowest $x \sim 10^{-4}$, especially for topologies with two forward jets. This hints to large contributions at low $x$ from initial state radiation of gluons close to the proton direction and unordered in transverse momentum. The Monte Carlo program in which gluon radiation is generated by the colour dipole model gives a good description of both the three- and the four-jet data in absolute normalisation and shape.

23 data tables

Differential cross section as a function of the minimum number of jet for events with at least 3-jets.

Differential cross section as a function of X for events with at least 3-jets.

Differential cross section for events with at least 3-jets as a function of the pseudorapidity of each jet.

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Production of V0 pairs in the hyperon experiment WA89

The WA89 collaboration Adamovich, M.I. ; Alexandrov, Yu.A. ; Baranov, S.P. ; et al.
Eur.Phys.J.C 52 (2007) 857-874, 2007.
Inspire Record 772833 DOI 10.17182/hepdata.11375

We present a comprehensive study of the inclusive production of V 0 V 0 pairs (V 0 =Lambda, Lambda-bar or K S ) by Sigma - and pi - of 340 GeV/ c momentum and neutrons of 260 GeV/ c mean momentum in copper and carbon targets. In particular, the de pendence of the x F spectra on the combination of beam-particle and produced V 0 V 0 pair is investigated and compared to predictions obtained from PYTHIA and QSGM calculations. The data and these predictions differ in many details, the agreement can at b est be termed as qualitative. A signal from decays of the tensor meson f? 2 (1525) was observed in the K S K S mass distribution and inclusive production cross sections were measured. No signal was found from the double-strange H-dibaryon decaying to Lamb daLambda.

98 data tables

V0 V0 cross section for N on CU target.

V0 V0 cross section for N on C target.

V0 V0 cross section for PI- on CU target.

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Multijet production at low x(Bj) in deep inelastic scattering at HERA.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Nucl.Phys.B 786 (2007) 152-180, 2007.
Inspire Record 750515 DOI 10.17182/hepdata.45528

Inclusive dijet and trijet production in deep inelastic $ep$ scattering has been measured for $10&lt;Q^2&lt;100$ GeV$^2$ and low Bjorken $x$, $10^{-4}&lt;x_{\rm Bj}&lt;10^{-2}$. The data were taken at the HERA $ep$ collider with centre-of-mass energy $\sqrt{s} = 318 \gev$ using the ZEUS detector and correspond to an integrated luminosity of $82 {\rm pb}^{-1}$. Jets were identified in the hadronic centre-of-mass (HCM) frame using the $k_{T}$ cluster algorithm in the longitudinally invariant inclusive mode. Measurements of dijet and trijet differential cross sections are presented as functions of $Q^2$, $x_{\rm Bj}$, jet transverse energy, and jet pseudorapidity. As a further examination of low-$x_{\rm Bj}$ dynamics, multi-differential cross sections as functions of the jet correlations in transverse momenta, azimuthal angles, and pseudorapidity are also presented. Calculations at $\mathcal{O}(\alpha_{s}^3)$ generally describe the trijet data well and improve the description of the dijet data compared to the calculation at $\mathcal{O}(\alpha_{s}^2)$.

66 data tables

Two jet cross section D(SIG)/DQ**2 as a function of Q**2.

Two jet cross section D(SIG)/DX as a function of X.

Two jet cross section D(SIG)/DET(P=4,RF=CM) as a function of ET(P=4,RF=CM).

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Measurement of D mesons production in deep inelastic scattering at HERA.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
JHEP 07 (2007) 074, 2007.
Inspire Record 749371 DOI 10.17182/hepdata.45530

Charm production in deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 82 pb^{-1}. Charm has been tagged by reconstructing D^{*+}, D^0, D^{+} and D_s^+ (+ c.c.) charm mesons. The charm hadrons were measured in the kinematic range p_T(D^{*+},D^0,D^{+}) > 3 GeV, p_T(D_s^+)>2 GeV and |\eta(D)| < 1.6 for 1.5 < Q^2 < 1000 GeV^2 and 0.02 < y < 0.7. The production cross sections were used to extract charm fragmentation ratios and the fraction of c quarks hadronising into a particular charm meson in the kinematic range considered. The cross sections were compared to the predictions of next-to-leading-order QCD, and extrapolated to the full kinematic region in p_T(D) and \eta(D) in order to determine the open-charm contribution, F_2^{c\bar{c}}(x,Q^2), to the proton structure function F_2.

24 data tables

Production cross section for all D0 mesons, those not originating fom D* decays and those originating from D* decays.

Production cross section for additional D* mesons (not decaying to D0) and all D* mesons.

Production cross section for D+ mesons.

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Diffractive Photoproduction of D*+/-(2010) at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Eur.Phys.J.C 51 (2007) 301-315, 2007.
Inspire Record 747652 DOI 10.17182/hepdata.45627

Diffractive photoproduction of D*+/-(2010) mesons was measured with the ZEUS detector at the ep collider HERA, using an integrated luminosity of 78.6 pb^{-1}. The D* mesons were reconstructed in the kinematic range: transverse momentum p_T(D*) > 1.9 GeV and pseudorapidity |eta(D*)| < 1.6, using the decay D*+ -> D0 pi+_s followed by D0 -> K- pi+ (+c.c.). Diffractive events were identified by a large gap in pseudorapidity between the produced hadronic state and the outgoing proton. Cross sections are reported for photon-proton centre-of-mass energies in the range 130 < W < 300 GeV and for photon virtualities Q^2 < 1 GeV^2, in two ranges of the Pomeron fractional momentum x_pom < 0.035 and x_pom < 0.01. The relative contribution of diffractive events to the inclusive D*+/-(2010) photoproduction cross section is about 6%. The data are in agreement with perturbative QCD calculations based on various parameterisations of diffractive parton distribution functions. The results are consistent with diffractive QCD factorisation.

12 data tables

Total cross section integrated over the given kinematic range.

Ratio of diffractive to inclusive D* cross section.

Differential cross sections for diffractive photoproduction of D*+- mesons as a function of X(NAME=POMERON).

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Bottom photoproduction measured using decays into muons in dijet events in e p collisions at s**(1/2) = 318-GeV.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Krakauer, D. ; et al.
Phys.Rev.D 70 (2004) 012008, 2004.
Inspire Record 636222 DOI 10.17182/hepdata.46356

The photoproduction of beauty quarks in events with two jets and a muon has been measured with the ZEUS detector at HERA using an integrated luminosity of 110 pb$^{- 1}$. The fraction of jets containing b quarks was extracted from the transverse momentum distribution of the muon relative to the closest jet. Differential cross sections for beauty production as a function of the transverse momentum and pseudorapidity of the muon, of the associated jet and of $x_{\gamma}^{jets}$, the fraction of the photon's momentum participating in the hard process, are compared with MC models and QCD predictions made at next-to-leading order. The latter give a good description of the data.

10 data tables

No description provided.

No description provided.

No description provided.

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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

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.

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Measurement of K0(S), Lambda, anti-Lambda production at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Eur.Phys.J.C 51 (2007) 1-23, 2007.
Inspire Record 734144 DOI 10.17182/hepdata.45796

The production of the neutral strange hadrons $K^{0}_{S}$, $\Lambda$ and $\bar{\Lambda}$ has been measured in $ep$ collisions at HERA using the ZEUS detector. Cross sections, baryon-to-meson ratios, relative yields of strange and charged light hadrons, $\Lambda$ ($\bar{\Lambda}$) asymmetry and polarization have been measured in three kinematic regions: $Q^2 > 25 \gev^2$: $5 < Q^2 < 25 \gev^2$: and in photoproduction ($Q^2 \simeq 0$). In photoproduction the presence of two hadronic jets, each with at least $5 \gev$ transverse energy, was required. The measurements agree in general with Monte Carlo models and are consistent with measurements made at $e^+ e^-$ colliders, except for an enhancement of baryon relative to meson production in photoproduction.

59 data tables

Differential K0S cross section in DIS events as a function of transverse momentum (lab). for Q**2 from 5 to 25 GeV**2.

Differential K0S cross section in DIS events as a function of transverse momentum (lab). for Q**2 > 25 GeV**2.

Differential K0S cross section in DIS events as a function of pseudorapidity (lab). for Q**2 from 5 to 25 GeV**2.

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Measurement of charm and beauty dijet cross sections in photoproduction at HERA using the H1 vertex detector.

The H1 collaboration Aktas, A. ; Andreev, V. ; Anthonis, T. ; et al.
Eur.Phys.J.C 47 (2006) 597-610, 2006.
Inspire Record 716144 DOI 10.17182/hepdata.45700

A measurement of charm and beauty dijet photoproduction cross sections at the ep collider HERA is presented. Events are selected with two or more jets of transverse momentum $p_t^{jet}_{1(2)}>11(8)$ GeV in the central range of pseudo-rapidity $-0.9<\eta^{jet}_{1(2)}<1.3$. The fractions of events containing charm and beauty quarks are determined using a method based on the impact parameter, in the transverse plane, of tracks to the primary vertex, as measured by the H1 central vertex detector. Differential dijet cross sections for charm and beauty, and their relative contributions to the flavour inclusive dijet photoproduction cross section, are measured as a function of the transverse momentum of the leading jet, the average pseudo-rapidity of the two jets and the observable $x_{\gamma}^{obs}$. Taking into account the theoretical uncertainties, the charm cross sections are consistent with a QCD calculation in next-to-leading order, while the predicted cross sections for beauty production are somewhat lower than the measurement.

22 data tables

Total dijet CHARM cross section in the defined kinematic range.

Total dijet BOTTOM cross section in the defined kinematic range.

Measured CHARM cross section as a function of PT.

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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

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

Triple differential cross section.

Triple differential cross section.

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

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Nucl.Phys.B 729 (2005) 492-525, 2005.
Inspire Record 687943 DOI 10.17182/hepdata.46048

Inclusive jet cross sections in photoproduction for events containing a $D^*$ meson have been measured with the ZEUS detector at HERA using an integrated luminosity of $78.6 {\rm pb}^{-1}$. The events were required to have a virtuality of the incoming photon, $Q^2$, of less than 1 GeV$^2$, and a photon-proton centre-of-mass energy in the range $130&lt;W_{\gamma p}&lt;280 {\rm GeV}$. The measurements are compared with next-to-leading-order (NLO) QCD calculations. Good agreement is found with the NLO calculations over most of the measured kinematic region. Requiring a second jet in the event allowed a more detailed comparison with QCD calculations. The measured dijet cross sections are also compared to Monte Carlo (MC) models which incorporate leading-order matrix elements followed by parton showers and hadronisation. The NLO QCD predictions are in general agreement with the data although differences have been isolated to regions where contributions from higher orders are expected to be significant. The MC models give a better description than the NLO predictions of the shape of the measured cross sections.

29 data tables

Cross section as a function of the jet transverse energy for INCLUSIVE events containing at least one D* meson in different jet pseudorapidity regions.

Cross section as a function of the jet transverse energy for INCLUSIVE events containing at least one D* meson in different jet pseudorapidity regions.

Cross section as a function of the jet transverse energy for INCLUSIVE events containing at least one D* meson in different jet pseudorapidity regions.

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Studies of QCD at e+ e- centre-of-mass energies between 91-GeV and 209-GeV.

The ALEPH collaboration Heister, A. ; Schael, S. ; Barate, R. ; et al.
Eur.Phys.J.C 35 (2004) 457-486, 2004.
Inspire Record 636645 DOI 10.17182/hepdata.12794

The hadronic final states observed with the ALEPH detector at LEP in ${\rm e}^ + {\rm e}^-$ annihilation

234 data tables

Mean charged particle multiplicities at different c.m. energies.

XP distribution at c.m. energy 133.0 GeV.

XP distribution at c.m. energy 161.0 GeV.

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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

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.

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