Prompt Charm Production in pp Collisions at √s = 7 TeV

Charm production at the LHC in pp collisions at √s = 7 TeV is studied with the LHCb detector. The decays D0 → K− π+, D+ → K− π+ π+, D⁎+ → D0(K− π+) π+, Ds+ → φ(K− K+)π+, Λc+ → p K− π+, and their charge conjugates are analysed in a data set corresponding to an integrated luminosity of 15 nb^−1. Differential cross-sections dσ/dp_T are measured for prompt production of the five charmed hadron species in bins of transverse momentum and rapidity in the region 0 < p_T < 8 GeV/c and 2.0 < y < 4.5. Theoretical predictions are compared to the measured differential cross-sections. The integrated cross-sections of the charm hadrons are computed in the above p_T-y range, and their ratios are reported. A combination of the five integrated cross-section measurements gives: σ(c anti-c)_p_T < 8 GeV/c, 2.0 < y < 4.5 = 1419 ± 12(stat) ± 116(syst) ± 65(frag) μb, where the uncertainties are statistical, systematic, and due to the fragmentation functions.