Charm Fragmentation Fractions and the Charm Fragmentation Function

The fragmentation of a charm quark to charmed hadrons in deep‐inelastic scattering has been studied using the H1 detector at HERA.The visible cross sections for inclusive D+, D0, Ds+ and D*+ meson production were determined making use of the secondary vertex displacement measured by the central silicon detector of H1 and fragmentation fractions and fragmentation ratios were extracted.To investigate the fraction of the charm quark’s momentum transferred to a charmed hadron, the differential cross section of D*‐meson has been measured as a function of two scaling observables.The parameters of the Peterson and Kartvelishvili fragmentation functions, as implemented in a model with leading‐order matrix elements, parton showers, string fragmentation and particle decays, were extracted from a fit to the measured distributions. The fits, using both observables, lead to the following ranges for the fragmentation parameters: 0.014 < ε < 0.036 (Peterson) and 4 < α < 6.8 (Kartvelishvili).