Physics – High Energy Physics – High Energy Physics - Experiment
Scientific paper
2005-08-09
Eur.Phys.J.C44:351-366,2005
Physics
High Energy Physics
High Energy Physics - Experiment
29 pages, 5 figures, 6 tables; minor text revisions
Scientific paper
10.1140/epjc/s2005-02397-3
The production of D^*+, D^0, D^+, D_s^+ and Lambda_c^+ charm hadrons and their antiparticles in ep scattering at HERA was measured with the ZEUS detector using an integrated luminosity of 79 pb^-1. The measurement has been performed in the photoproduction regime with the exchanged-photon virtuality Q^2 < 1 GeV^2 and for photon-proton centre-of-mass energies in the range 130 < W < 300 GeV. The charm hadrons were reconstructed in the range of transverse momentum p_T(D, Lambda_c) > 3.8 GeV and pseudorapidity |eta(D, Lambda_c)| < 1.6. The production cross sections were used to determine the ratio of neutral and charged D-meson production rates, R_u/d, the strangeness-suppression factor, gamma_s, and the fraction of charged D mesons produced in a vector state, P_v^d. The measured R_u/d and gamma_s values agree with those obtained in deep inelastic scattering and in e^+e^- annihilations. The measured P_v^d value is smaller than, but consistent with, the previous measurements. The fractions of c quarks hadronising as a particular charm hadron, f(c -> D, Lambda_c), were derived in the given kinematic range. The measured open-charm fragmentation fractions are consistent with previous results, although the measured f(c -> D^*+) is smaller and f(c -> Lambda_c^+) is larger than those obtained in e^+e^- annihilations. These results generally support the hypothesis that fragmentation proceeds independently of the hard sub-process.
No associations
LandOfFree
Measurement of charm fragmentation ratios and fractions in photoproduction at HERA does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Measurement of charm fragmentation ratios and fractions in photoproduction at HERA, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Measurement of charm fragmentation ratios and fractions in photoproduction at HERA will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-576658