Measurement of D + and Λ c + production in deep inelastic scattering at HERA

Charm production in deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 120 pb -1 . The hadronic decay channels D + K 0 S + , + c pK 0 S and + c + , and their charge conjugates, were reconstructed. The presence of a neutral strange hadron in the final state reduces the combinatorial background and extends the measured sensitivity into the low transverse momentum region. The kinematic range is 0 < p T (D + , + c ) < 10 GeV, |(D + , + c )| < 1.6, 1.5 < Q 2 < 1000 GeV 2 and 0.02 < y < 0.7. Inclusive and differential cross sections for the production of D + mesons are compared to next-to-leading-order QCD predictions. The fraction of c quarks hadronising into + c baryons is extracted.