Measurement of beauty and charm production in pp collisions at s=5.02 TeV via non-prompt and prompt D mesons

The p(T)-differential production cross sections of prompt and non-prompt (produced in beauty-hadron decays) D mesons were measured by the ALICE experiment at midrapidity (|y|< 0.5) in proton-proton collisions at s = 5.02 TeV. The data sample used in the analysis corresponds to an integrated luminosity of (19.3 0.4) nb(-1). D mesons were reconstructed from their decays D-0 -> K-pi (+), D+-> K-pi (+)pi (+), and Ds+-> phi pi+-> K-K+pi+ and their charge conjugates. Compared to previous measurements in the same rapidity region, the cross sections of prompt D+ and Ds+ mesons have an extended p(T) coverage and total uncertainties reduced by a factor ranging from 1.05 to 1.6, depending on p(T), allowing for a more precise determination of their p(T)-integrated cross sections. The results are well described by perturbative QCD calculations. The fragmentation fraction of heavy quarks to strange mesons divided by the one to non-strange mesons, f(s)/(f(u) + f(d)), is compatible for charm and beauty quarks and with previous measurements at different centre-of-mass energies and collision systems. The bb production cross section per rapidity unit at midrapidity, estimated from non-prompt D-meson measurements, is dsigma bb/dyy<0.5=34.5 +/- 2.4stat-2.9+4.7tot.syst mu b. It is compatible with previous measurements at the same centre-of-mass energy and with the cross section pre- dicted by perturbative QCD calculations.

Automated summary

The ALICE experiment measured the p(T)-differential production cross sections of prompt and non-prompt D mesons in proton-proton collisions, showing extended p(T) coverage and reduced total uncertainties compared to previous measurements. The results are well described by perturbative QCD calculations, and the fragmentation fraction of heavy quarks to strange mesons is found to be compatible with previous measurements at different energies and collision systems. The bb production cross section at midrapidity is consistent with previous measurements and theoretical predictions.