Study of flavor dependence of the baryon-to-meson ratio in proton-proton collisions at $\sqrt{s} = 13$ TeV

TL;DR

This paper reports the first measurements of non-prompt D0 and Lambda_c+ hadrons from beauty decays at 13 TeV proton-proton collisions, providing insights into beauty quark hadronization and baryon-to-meson ratios.

Contribution

It presents the first measurement of non-prompt charm hadron production from beauty decays at 13 TeV and compares baryon-to-meson ratios across different collision systems.

Findings

Measured b-bbar cross section at midrapidity: 83.1 μb.

Non-prompt Lambda_c+/D0 ratio similar to prompt charm and light hadron ratios.

Higher non-prompt Lambda_c+/D0 ratio than in e+e- collisions.

Abstract

The production cross sections of ${\rm D^0}$ and $\Lambda^+_{\rm c}$ hadrons originating from beauty-hadron decays (i.e. non-prompt) were measured for the first time at midrapidity ($|y|<0.5$) by the ALICE Collaboration in proton-proton collisions at a center-of-mass energy $\sqrt{s}=13$ TeV. They are described within uncertainties by perturbative QCD calculations employing the fragmentation fractions of beauty quarks to baryons measured at forward rapidity by the LHCb Collaboration. The ${\rm b\overline{b}}$ production cross section per unit of rapidity at midrapidity, estimated from these measurements, is ${\rm d}\sigma_{\rm b\overline{b}}/{\rm d}y|_{|y|<0.5} = 83.1 \pm 3.5 (\mathrm{stat.}) \pm 5.4(\mathrm{syst.}) ^{+12.3}_{-3.2} (\mathrm{extrap.})\,\mu$b. The baryon-to-meson ratios are computed to investigate the hadronization mechanism of beauty quarks. The non-prompt $\Lambda^+_{\rm c}/{\rm D^0}$ production ratio has a similar trend to the one measured for the promptly produced charmed particles and to the p$/\pi^+$ and $\Lambda/{\rm K^0_S}$ ratios, suggesting a similar baryon-formation mechanism among light, strange, charm, and beauty hadrons. The $p_{\rm T}$-integrated non-prompt $\Lambda_{\rm c}/{\rm D^0}$ ratio is found to be significantly higher than the one measured in e$^+$e$^-$ collisions.