Measurement of charm fragmentation fractions in photoproduction at HERA

The production of D 0 , D *+ , D + , D s + and Λ c + charm hadrons and their antiparticles in ep scattering at HERA has been studied with the ZEUS detector, using a total integrated luminosity of 372 pb -1 . The fractions of charm quarks hadronising into a particular charm hadron were derived. In addition, the ratio of neutral to charged D-meson production rates, the fraction of charged D mesons produced in a vector state, and the stangeness-suppression factor have been determined. The measurements have been performed in the photoproduction regime. The charm hadrons were reconstructed in the range of transverse momentum p T > 3.8 GeV and pseudorapidity |η| + e - experiments. The data support the hypothesis that fragmentation is independent of the production process. © 2013 SISSA.