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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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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Dijet production in diffractive deep inelastic scattering at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Eur.Phys.J.C 52 (2007) 813-832, 2007.
Inspire Record 757973 DOI 10.17182/hepdata.45428

The production of dijets in diffractive deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of $61 \pbi$. The dijet cross section has been measured for virtualities of the exchanged virtual photon, $5 < Q^2 < 100 \gev^2$, and $\gamma^{*} p$ centre-of-mass energies, 100 < W < 250 GeV. The jets, identified using the inclusive k_{T} algorithm in the $\gamma^* p$ frame, were required to have a transverse energy $E^*_{T, \rm jet} > 4 \gev$ and the jet with the highest transverse energy was required to have $E^*_{T,\rm jet} > 5 \gev$. All jets were required to be in the pseudorapidity range $-3.5 < \eta^*_{\rm jet} < 0$. The differential cross sections are compared to leading-order predictions and next-to-leading-order QCD calculations based on recent diffractive parton densities extracted from inclusive diffractive deep inelastic scattering data.

17 data tables

Total di-jet cross section SIG as a function of Q**2 .

Distribution of D(SIG)/DQ**2 as a function of Q**2 .

Distribution of D(SIG)/DW as a function of W .

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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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Photoproduction of D*+- mesons associated with a leading neutron.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Krakauer, D. ; et al.
Phys.Lett.B 590 (2004) 143-160, 2004.
Inspire Record 642709 DOI 10.17182/hepdata.46281

The photoproduction of $D^{*\pm} (2010)$ mesons associated with a leading neutron has been observed with the ZEUS detector in $ep$ collisions at HERA using an integrated luminosity of 80 pb$^{-1}$. The neutron carries a large fraction, {$x_L>0.2$}, of the incoming proton beam energy and is detected at very small production angles, {$\theta_n<0.8$ mrad}, an indication of peripheral scattering. The $D^*$ meson is centrally produced with pseudorapidity {$|\eta|<1.5$}, and has a transverse momentum {$p_{\it T} > 1.9$ GeV}, which is large compared to the average transverse momentum of the neutron of 0.22 GeV. The ratio of neutron-tagged to inclusive $D^*$ production is $8.85\pm 0.93({\rm stat.})^{+0.48}_{-0.61}({\rm syst.})\%$ in the photon-proton center-of-mass energy range {$130 <W<280$ GeV}. The data suggest that the presence of a hard scale enhances the fraction of events with a leading neutron in the final state.

8 data tables

Integrated cross section. The first DSYS error includes the uncertainty in the luminosity and the second DSYS error is due to the knowledge of the branching ratios.

No description provided.

No description provided.

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Measurement of inelastic J/psi production in deep inelastic scattering at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Eur.Phys.J.C 44 (2005) 13-25, 2005.
Inspire Record 682022 DOI 10.17182/hepdata.46122

The inelastic production of J/psi mesons in e p collisions has been studied with the ZEUS detector at HERA using an integrated luminosity of 109 pb-1. The J/psi mesons were identified using the decay channel J/psi -> mu+ mu-. The measurements were performed in the kinematic range 2 < Q^2< 80 Gev^2, 50 < W < 250 Gev, 0.2 < z <0.9 and -1.6 < Ylab < 1.3, where Q^2 is the virtuality of the exchanged photon, W is the photon-proton centre-of-mass energy, z is the fraction of the photon energy carried by the J/psi meson in the proton rest frame and Ylab is the rapidity of the J/psi in the laboratory frame. The measured cross sections are compared to theoretical predictions within the non-relativistic QCD framework including colour-singlet and colour-octet contributions, as well as to predictions based on the kT-factorisation approach. Calculations of the colour-singlet process generally agree with the data, whereas inclusion of colour-octet terms spoils this agreement.

11 data tables

Integrated cross section for the process E P --> E J/PSI X.

Differential cross section as a function of Z.

Differential cross section as a function of W.

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Study of hadronic final states from double tagged gamma gamma events at LEP.

The ALEPH collaboration Heister, A. ; Schael, S. ; Barate, R. ; et al.
CERN-EP-2003-025, 2003.
Inspire Record 619958 DOI 10.17182/hepdata.49702

The interaction of virtual photons is investigated using double tagged gammagamma events with hadronic final states recorded by the ALEPH experiment at e^+e^- centre-of-mass energies between 188 and 209 GeV. The measured cross section is compared to Monte Carlo models, and to next-to-leading-order QCD and BFKL calculations.

10 data tables

Differential cross section as a function of the relative energy of the scattered electrons.

Differential cross section as a function of the polar angle THETA of the scattered electrons.

Differential cross section as a function of the virtuality Q**2 of the photons.

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Inelastic leptoproduction of J / psi mesons at HERA

The H1 collaboration Adloff, C. ; Andreev, V. ; Andrieu, B. ; et al.
Eur.Phys.J.C 25 (2002) 41-53, 2002.
Inspire Record 586978 DOI 10.17182/hepdata.46581

The leptoproduction of J/psi mesons is studied in inelastic reactions for four momentum transfers 2<Q^2<100GeV^2. The data were taken with the H1 detector at the electron proton collider HERA and correspond to an integrated luminosity of 77 pb-1. Single differential and double differential cross sections are measured with increased precision compared with previous analyses. New leading order calculations within the non-relativistic QCD factorisation approach including colour octet and colour singlet contributions are compared with the data and are found to give a reasonable description of most distributions. An exception is the shape of the distribution in the J/psi fractional energy, z, which deviates significantly from that of the data. Comparisons with photoproduction are made and the polarisation of the produced J/psi meson is analysed.

23 data tables

J/PSI leptoproduction differential cross section as a function of Q**2.

J/PSI leptoproduction differential cross section as a function of Z.

J/PSI leptoproduction differential cross section as a function of W.

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Measurement of diffractive production of D*(2010)+- mesons in deep inelastic scattering at HERA.

The ZEUS collaboration Chekanov, S. ; Krakauer, D. ; Magill, S. ; et al.
Phys.Lett.B 545 (2002) 244-260, 2002.
Inspire Record 588104 DOI 10.17182/hepdata.46583

Diffractive production of D*+-(2010) mesons in deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 44.3 pb-1. Diffractive charm production is identified by the presence of a large rapidity gap in the final state of events in which a D*+-(2010) meson is reconstructed in the decay channel D*+ -> (D0 -> K-pi+) pi+ (+ charge conjugate). Differential cross sections when compared with theoretical predictions indicate the importance of gluons in such diffractive interactions.

9 data tables

Measurment of total diffractive cross section and ratio to inclusive DIS cross section.

Ratio of diffractive to inclusive D*+- production w.r.t. Q**2.

Ratio of diffractive to inclusive D*+- production w.r.t. W.

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Measurement of D*+- meson production and F2(c) in deep inelastic scattering at HERA.

The H1 collaboration Adloff, C. ; Andreev, V. ; Andrieu, B. ; et al.
Phys.Lett.B 528 (2002) 199-214, 2002.
Inspire Record 561885 DOI 10.17182/hepdata.46834

The inclusive production of D^{*+-}(2010) mesons in deep-inelastic scattering is studied with the H1 detector at HERA. In the kinematic region 1<Q^2<100 GeV^2 and 0.05<y<0.7 an e^+p cross section for inclusive D^(*+-) meson production of 8.50+- 0.42 (stat.)^(+1.21)_(-1.00) (syst.) nb is measured in the visible range p_(tD^*)>1.5 GeV and |\eta_(D^*)|<1.5. Single and double differential inclusive D^(*+-) meson cross sections are compared to perturbative QCD calculations in two different evolution schemes. The charm contribution to the proton structure, F_2^c(x,Q^2), is determined by extrapolating the visible charm cross section to the full phase space. This contribution is found to rise from about 10% at Q^2 = 1.5 GeV^2 to more than 25% at Q^2 = 60 GeV^2 corresponding to x values ranging from 5*10^(-5) to 3*10^(-3)$.

14 data tables

The inclusive cross section for D*+- production. The second DSYS error is related to the changes in efficiency obtained by using different Monte Carlo generators and varying the model parameters.

Single differential visible cross section as a function of W.

Single differential visible cross section as a function of PT.

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