JOURNAL OF HIGH ENERGY PHYSICS, vol.2012, no.7, 2012 (SCI-Expanded)
The p(t)-differential production cross sections of the prompt (B feed-down subtracted) charmed mesons D-0, D+, and D*(+) in the rapidity range vertical bar y vertical bar < 0.5, and for transverse momentum 1 < p(t) < 12 GeV/c, were measured in proton-proton collisions at root s = 2.76 TeV with the ALICE detector at the Large Hadron Collider. The analysis exploited the hadronic decays D-0 -> K-pi(+), D+ -> K-pi(+)pi(+), D*(+) -> D-0 pi(+), and their charge conjugates, and was performed on a L-int = 1.1 nb(-1) event sample collected in 2011 with a minimum-bias trigger. The total charm production cross section at root s = 2.76 TeV and our previous measurements at root s = 7 TeV. The results were compared to existing measurements and to perturbative-QCD calculations. The fraction of c(d)over-bar D mesons produced in a vector state was also determined.