Date

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Measurement of exclusive rho+ rho- production in mid-virtuality two-photon interactions and study of the gamma gamma* --> rho rho process at LEP.

The L3 collaboration Achard, P. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 615 (2005) 19-30, 2005.
Inspire Record 680120 DOI 10.17182/hepdata.48814

Exclusive rho+rho- production in two-photon collisions between a quasi-real photon, gamma, and a mid-virtuality photon, gamma*, is studied with data collected at LEP at centre-of-mass energies root(s)=183-209GeV with a total integrated luminosity of 684.8pb^-1. The cross section of the gamma gamma* -> rho+ rho- process is determined as a function of the photon virtuality, Q^2, and the two-photon centre-of-mass energy, W_gg, in the kinematic region: 0.2GeV^2 < Q^2 <0.85GeV^2 and 1.1GeV < W_gg < 3GeV. These results, together with previous L3 measurements of rho0 rho0 and rho+ rho- production, allow a study of the gamma gamma* -> rho rho process over the Q^2-region 0.2GeV^2 < Q^2 < 30 GeV^2.

4 data tables

Production cross section as a function of Q**2. Differential cross sectionsare corrected to the centre of each bin.

Production cross section for two-photon data as a function of Q**2.

Production cross section as a function of W.

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Measurement of beauty production at HERA using events with muons and jets

The H1 collaboration Aktas, A. ; Andreev, V. ; Anthonis, T. ; et al.
Eur.Phys.J.C 41 (2005) 453-467, 2005.
Inspire Record 676166 DOI 10.17182/hepdata.110966

A measurement of the beauty production cross section in ep collisions at a centre-of-mass energy of 319 GeV is presented. The data were collected with the H1 detector at the HERA collider in the years 1999-2000. Events are selected by requiring the presence of jets and muons in the final state. Both the long lifetime and the large mass of b-flavoured hadrons are exploited to identify events containing beauty quarks. Differential cross sections are measured in photoproduction, with photon virtualities Q^2 < 1 GeV^2, and in deep inelastic scattering, where 2 < Q^2 < 100 GeV^2. The results are compared with perturbative QCD calculations to leading and next-to-leading order. The predictions are found to be somewhat lower than the data.

10 data tables

Muons and jets from beauty photoproduction, pseudorapidity.

Muons and jets from beauty photoproduction, muon transverse momentum.

Muons and jets from beauty photoproduction, leading jet transverse momentum

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Measurement of dijet cross sections in e p interactions with a leading neutron at HERA.

The H1 collaboration Aktas, A. ; Andreev, V. ; Anthonis, T. ; et al.
Eur.Phys.J.C 41 (2005) 273-286, 2005.
Inspire Record 669251 DOI 10.17182/hepdata.46199

Measurements are reported of the production of dijet events with a leading neutron in ep interactions at HERA. Differential cross sections for photoproduction and deep inelastic scattering are presented as a function of several kinematic variables. Leading order QCD simulation programs are compared with the measurements. Models in which the real or virtual photon interacts with a parton of an exchanged pion are able to describe the data. Next-to-leading order perturbative QCD calculations based on pion exchange are found to be in good agreement with the measured cross sections. The fraction of leading neutron dijet events with respect to all dijet events is also determined. The dijet events with a leading neutron have a lower fraction of resolved photon processes than do the inclusive dijet data.

14 data tables

Differential e p photoproduction cross section as a function of the jet transverse energy.

Differential e p photoproduction cross section as a function of JET pseudorapidity.

Differential e p photoproduction cross section as a function of JET X(C=GAMMA).

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Measurement of exclusive rho0 rho0 production in mid-virtuality two-photon interactions at LEP.

The L3 collaboration Achard, P. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 604 (2004) 48-60, 2004.
Inspire Record 662726 DOI 10.17182/hepdata.48649

Exclusive rho^0 rho^0 production in two-photon collisions between a quasi-real and a mid-virtuality photon is studied with data collected at LEP at centre-of-mass energies 183GeV < sqrt{s} < 209GeV with a total integrated luminosity of 684.8/pb. The cross section of the process gamma gamma* -> rho^0 rho^0 is determined as a function of the photon virtuality, q^2, and the two-photon centre-of-mass energy, Wgg, in the kinematic region: 0.2GeV^2 < q^2 < 0.85GeV^2 and 1.1GeV < Wgg < 3GeV.

4 data tables

Production cross section as a function of Q**2. Differential cross sectionsare corrected to the centre of each bin.

Production cross section for two-photon data as a function of Q**2.

Production cross section as a function of W.

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Inclusive production of D+, D0, D/s+ and D*+ mesons in deep inelastic scattering at HERA.

The H1 collaboration Aktas, A. ; Andreev, V. ; Anthonis, T. ; et al.
Eur.Phys.J.C 38 (2005) 447-459, 2005.
Inspire Record 657925 DOI 10.17182/hepdata.46028

Inclusive production cross sections are measured in deep inelastic scattering at HERA for meson states composed of a charm quark and a light antiquark or the charge conjugate. The measurements cover the kinematic region of photon virtuality 2 < Q^2 < 100 GeV^2, inelasticity 0.05 < y < 0.7, D meson transverse momenta p_t(D) > 2.5 GeV and pseudorapidity |eta(D)| < 1.5. The identification of the D-meson decays and the reduction of the combinatorial background profit from the reconstruction of displaced secondary vertices by means of the H1 silicon vertex detector. The production of charmed mesons containing the light quarks u, d and s is found to be compatible with a description in which the hard scattering is followed by a factorisable and universal hadronisation process.

16 data tables

Inclusive D+- electroproduction cross section.

Inclusive D0 electroproduction cross section.

Inclusive D/S+- electroproduction cross section.

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Measurement of exclusive rho+ rho- production in high-Q**2 two-photon collisions at LEP.

The L3 collaboration Achard, P. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 597 (2004) 26-38, 2004.
Inspire Record 654177 DOI 10.17182/hepdata.48589

Exclusive rho^+ rho^- production in two-photon collisions involving a single highly-virtual photon is studied with data collected at LEP at centre-of-mass energies 89 GeV < \sqrt{s} < 209 GeV with a total integrated luminosity of 854.7 pb^-1. The cross section of the process gamma gamma^* -> rho^+ rho^- is determined as a function of the photon virtuality, Q^2, and the two-photon centre-of-mass energy, W_gg, in the kinematic region: 1.2 GeV^2 < Q^2 < 30 GeV^2 and 1.1 GeV < W_gg < 3 GeV. The \rho^+\rho^- production cross section is found to be of the same magnitude as the cross section of the process gamma gamma^* -> rho^0 rho^0, measured in the same kinematic region by L3, and to have similar W_gg and Q^2 dependences.

9 data tables

Cross sections for the reaction E+ E- --> E+ E- RHO+ RHO-. The differentialcross sections are corrected to the centre of each bin.

Cross sections for the two photon production of RHO+ RHO-.

Differential cross section for the process E+ E- --> E+ E- (RHO+ PI- PI0 + RHO+ RHO- PI0 PI0) corrected to bin centre.

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Measurement of exclusive rho0 rho0 production in two photon collisions at high Q**2 at LEP

The L3 collaboration Achard, P. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 568 (2003) 11-22, 2003.
Inspire Record 619620 DOI 10.17182/hepdata.48855

Exclusive rho rho production in two-photon collisions involving a single highly virtual photon is studied with data collected at LEP at centre-of-mass energies 89GeV < \sqrt{s} < 209GeV with a total integrated luminosity of 854.7pb^-1 The cross section of the process gamma gamma^* -> rho rho is determined as a function of the photon virtuality, Q^2 and the two-photon centre-of-mass energy, Wgg, in the kinematic region: 1.2GeV^2 < Q^2 < 30GeV^2 and 1.1GeV < Wgg < 3GeV.

7 data tables

Production cross sections as a function of Q**2. The differential cross sections are corrected to the centre of each bin.

Production cross section for the two photon data as a function of Q**2.

Differential cross section for non-resonance and RHO0 RHO0 data corrected to the centre of each bin.

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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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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.

21 data tables

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.

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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

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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