Measurement of beauty and charm production in pp collisions at <mml:msqrt>s</mml:msqrt>=5.02 TeV via non-prompt and prompt D mesons

作者：Acharya, S.; Adamova, D.; Adler, A.; Adolfsson, J.; Rinella, G. Aglieri; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Akbar, Z.; Akindinov, A.; Al-Turany, M.; Aleksandrov, D.; Alessandro, B.; Alfanda, H. M.; Alfaro Molina, R.; Ali, B.; Ali, Y.; Alici, A.; Alizadehvandchali, N.; Alkin, A.; Alme, J.; Alt, T.; Altenkamper, L.; Altsybeev, I; Anaam, M. N.; Andrei, C.; Andreou, D.; Andronic, A.; Anguelov, V; Antinori, F.; Antonioli, P.; Anuj, C.; Apadula, N.; Aphecetche, L.

来源：JOURNAL OF HIGH ENERGY PHYSICS, 2021, (5): 220.

DOI：10.1007/JHEP05(2021)220

• Heavy Ion Experiments

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 <mml:msqrt>s</mml:msqrt> = 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+</mml:msubsup>-> 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+</mml:msubsup> 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<overbar></mml:mover> production cross section per rapidity unit at midrapidity, estimated from non-prompt D-meson measurements, is d<mml:msub>sigma bb<overbar></mml:mover>/dy<mml:mfenced open="|"><mml:msub><mml:mfenced close="|" open="|">y</mml:mfenced><0.5=34.5 +/- 2.4<mml:mfenced close=")" open="(">stat</mml:mfenced>-2.9<mml:mo>+4.7<mml:mfenced close=")" open="(">tot<mml:mo>.syst</mml:mfenced></mml:mfenced> 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.<fig id="Figa" position="anchor"><graphic position="anchor" specific-use="HTML" mime-subtype="JPEG" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="MediaObjects/13130_2021_15783_Figa_HTML.jpg" id="MO1"></graphic