XXVIII International Workshop on Deep-Inelastic Scattering and Related Subjects

Measurements of beauty-hadron production in pp and Pb--Pb collisions with ALICE

14 Apr 2021, 08:00

18m

Virtual (Stony Brook, NY)

Contributed Talk QCD with Heavy Flavors and Hadronic Final States QCD with Heavy Flavors and Hadronic Final States

Speaker

Fabrizio Grosa (INFN Torino)

Description

In hadronic collisions, beauty quarks are produced in hard-scattering processes with large momentum transfer. The production of hadrons containing beauty quarks provides a very important test of perturbative QCD calculations in pp collisions. The measurement of the production of beauty-strange mesons relative to that of beauty hadrons without strange-quark content is useful to study the fragmentation of beauty quarks into beauty mesons. Moreover, the measurement of beauty-hadron production in heavy-ion collisions is a unique tool to investigate the properties of the colour-deconfined medium created, the quark--gluon plasma (QGP). In particular, beauty quarks, being four times heavier than charm quarks, can be exploited to study the mass dependence of the in-medium energy loss.

In this contribution, the latest results about beauty-hadron production via non-prompt ${\mathrm{D}}^0$, ${\mathrm{D}}^{+}$, ${{\mathrm{D}}_{\mathrm{s}}}^{+}$ and $\mathrm{J}/\psi$ mesons, as well as beauty-decay electrons and dielectrons in pp collisions at a centre-of-mass energy of $\sqrt{s}=5.02$ TeV, and their comparison to pQCD calculations will be presented. The ratio of the beauty-quark fragmentation fraction to strange beauty mesons and that to non-strange beauty mesons will be compared to the same quantity for the charm sector and to previous measurements in ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$, ${\mathrm{e}}^{\pm }\mathrm{p}$, and $\mathrm{p}\bar{\mathrm{p}}$ collisions. The extrapolated $\mathrm{b}\bar{\mathrm{b}}$ cross section per unit of rapidity at midrapidity obtained from these measurements will be compared to pQCD calculations with next-to-leading order accurancy with all-order resummation of next-to-leading logarithms (FONLL) and with next-to-next leading order (NNLO) accurancy. Finally, the production of non-prompt ${\mathrm{D}}^0$ mesons in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV will be compared to the one of prompt ${\mathrm{D}}^0$ mesons and to different theoretical models.

Presentation materials

DIS_ALICE_beauty_Grosa.pdf

Youtube Link