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

The pT-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 D0 → K−π+, D+ → K−π+π+, and D+s → φπ+ → K−K+π + and their charge conjugates. Compared to previous measurements in the same rapidity region, the cross sections of prompt D+ and D+ s mesons have an extended pT coverage and total uncertainties reduced by a factor ranging from 1.05 to 1.6, depending on pT, allowing for a more precise determination of their pT 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, fs/(fu + fd), 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 dσbb/dy||y|<0.5 = 34.5±2.4(stat)+4.7−2.9(tot. syst) µb. It is compatible with previous measurements at the same centre-of-mass energy and with the cross section predicted by perturbative QCD calculations.

Heavy Ion Experiments ; quantum chromodynamics: perturbation theory ; charm: production ; pp: scattering ; rapidity ; fragmentation ; strange meson ; heavy quark ; ALICE ; experimental results

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