Beauty and charm production in pp collisions via D-meson measurements with ALICE

<!--HTML--><p>Measurements of the production of hadrons containing charm or beauty quarks in proton-proton collisions provide an important test of quantum chromodynamics calculations. They also set the reference for the respective measurements in heavy-ion collisions, where the formation and properties of the quark-gluon plasma are investigated.</p> <p>The excellent particle identification, track and decay-vertex reconstruction capabilities of the ALICE experiment, together with machine-learning techniques for multi-class classification, are exploited to separate the signal of non-prompt D mesons (produced in beauty-hadron decays) from that of prompt D mesons (produced in the charm-quark fragmentation) and the combinatorial background. The machine-learning approach also permits us to improve the precision of the prompt $\mathrm{D^+}$ and $\mathrm{D_s^+}$ measurements and to extend their transverse-momentum reach down to $0$ and $1~\mathrm{GeV}/c$, respectively. These measurements allow us to investigate the production and hadronization of charm and beauty quarks in proton-proton collisions.</p> <p>In this seminar, the most recent results of the ALICE Collaboration on the production of prompt and non-prompt $\mathrm{D^0}$, $\mathrm{D^+}$, and $\mathrm{D_s^+}$ mesons at midrapidity in proton--proton collisions at $\sqrt{s} = 5.02~\mathrm{TeV}$ are presented. The fragmentation fraction to strange mesons divided by the one to non-strange mesons, $f_\mathrm{s} / (f_\mathrm{u} +f_\mathrm{d})$, is reported for charm and beauty quarks. The measured $\mathrm{b\bar{b}}$ production cross section at midrapidity per unit of rapidity is compared to FONLL calculations and the recent and more accurate NNLO calculations.<br /> ALICE Collaboration, arXiv:2102.13601</p> ALICE seminar - 30 march 2021: https://cern.zoom.us/j/68594692624?pwd=ME5IenNJSysybDZERmRKVUxUKzN5dz09