Measurement of charm fragmentation ratios and fractions in photoproduction at HERA

Abstract

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.

29 pages, 5 figures, 6 tables; minor text revisions

References in corpus (3)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• Inclusive Production of D^+, D^0, D_s^+ and D^*+ Mesons in Deep Inelastic Scattering at HERA
• Search for a narrow charmed baryonic state decaying to D^*+/- p^-/+ in ep collisions at HERA

Cited by in corpus (34)

• Heavy-flavour spectra in high energy nucleus-nucleus collisions
• Heavy Neutral Leptons at FASER
• Combined analysis of charm-quark fragmentation-fraction measurements
• Heavy flavours in AA collisions: production, transport and final spectra
• ${\Lambda }_{\mathrm{c}}^{+}$ production in pp collisions at $\sqrt{s}=7$ TeV and in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• D${}_s^{+}$ meson production at central rapidity in proton-proton collisions at $\sqrt{s}$ = 7 TeV
• The Hadronic Final State at HERA
• Measurement of $D^{\ast \pm }$, $D^{\pm }$ and $D_s^{\pm }$ meson production cross sections in $pp$ collisions at $\sqrt{s}=7$ TeV with the ATLAS detector
• Measurement of electrons from beauty hadron decays in pp collisions at $\sqrt{s}=7$ TeV
• Collider Physics at HERA
• ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}$ production in pp and in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• Measurement of prompt D${}^0$, ${\Lambda }_c^{+}$, and ${\Sigma }_c^{0,++}$(2455) production in pp collisions at $\sqrt{s}=13$ TeV
• Beauty production in pp collisions at $\sqrt{s}$ = 2.76 TeV measured via semi-electronic decays
• Measurement of the D* Meson Production Cross Section and F_2^{ccbar}, at High Q^2, in ep Scattering at HERA
• Measurement of the cross sections of ${\Xi }_{\mathrm{c}}^0$ and ${\Xi }_{\mathrm{c}}^{+}$ baryons and branching-fraction ratio BR(${\Xi }_{\mathrm{c}}^0\to {\Xi }^{-}{\mathrm{e}}^{+}{\nu }_{\mathrm{e}}$)/BR(${\Xi }_{\mathrm{c}}^0\to {\Xi }^{-}{\pi }^{+}$) in pp collisions at 13 TeV
• Study of Charm Fragmentation into D^{*\pm} Mesons in Deep-Inelastic Scattering at HERA
• Production of excited charm and charm-strange mesons at HERA
• Measurement of the production cross section of prompt ${\Xi }_{\mathrm{c}}^0$ baryons at midrapidity in pp collisions at $\sqrt{s}$ = 5.02 TeV
• Diffractive Photoproduction of D*+/-(2010) at HERA
• Beauty photoproduction using decays into electrons at HERA
• Charm and Bottom Hadrons in Hot Hadronic Matter
• Production of the excited charm mesons D_1 and D^*_2 at HERA
• Measurement of D^{+} and Lambda_{c}^{+} production in deep inelastic scattering at HERA
• Production of doubly charmed baryons nearly at rest
• Measurement of heavy-quark jet photoproduction at HERA
• EIC Physics from An All-Silicon Tracking Detector
• Measurement of D mesons Production in Deep Inelastic Scattering at HERA
• Towards the understanding of heavy quarks hadronization: from leptonic to heavy-ion collisions
• Measurement of D*+- meson production in ep scattering at low Q^2
• Measurement of ${\Xi }_c^{+}$ production in $p$Pb collisions at $\sqrt{s_{NN}}=8.16$ TeV at LHCb
• Measurements of $D_S^{\pm }$-meson production in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV in STAR
• Production properties of the Doubly Charmed Baryons at the large Feynman-X
• Spin Dependence of Heavy Quark Fragmentation
• D meson-hadron angular correlations in pp and p-Pb collisions with ALICE at the LHC