Study of flavor dependence of the baryon-to-meson ratio in proton-proton collisions at s =13 TeV

The production cross sections of D0 and Λ+c hadrons originating from beauty-hadron decays (i.e., nonprompt) 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 √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 b¯b production cross section per unit of rapidity at midrapidity, estimated from these measurements, is dσb¯b/dy||y|<0.5=83.1±3.5(stat)±5.4(syst)+12.3−3.2(extrap)  μb. The baryon-to-meson ratios are computed to investigate the hadronization mechanism of beauty quarks. The nonprompt Λ+c/D0 production ratio has a similar trend to the one measured for the promptly produced charmed particles and to the p/π+ and Λ/K0S ratios, suggesting a similar baryon-formation mechanism among light, strange, charm, and beauty hadrons. The pT -integrated nonprompt Λ+c/D0 ratio is found to be significantly higher than the one measured in e+e− collisions.