Measurement of beauty production via non-prompt charm hadrons in p–Pb collisions at sNN = 5.02 TeV

The production cross sections of D⁰, D⁺, and Λc+ hadrons originating from beauty-hadron decays (i.e. non-prompt) were measured for the first time at midrapidity in proton–lead (p–Pb) collisions at the center-of-mass energy per nucleon pair of sNN = 5.02 TeV. Nuclear modification factors (R_pPb) of non-prompt D⁰, D⁺, and Λc+ are calculated as a function of the transverse momentum (p_T) to investigate the modification of the momentum spectra measured in p–Pb collisions with respect to those measured in proton–proton (pp) collisions at the same energy. The R_pPb measurements are compatible with unity and with the measurements in the prompt charm sector, and do not show a significant p_T dependence. The p_T-integrated cross sections and p_T-integrated R_pPb of non-prompt D⁰ and D⁺ mesons are also computed by extrapolating the visible cross sections down to p_T = 0. The non-prompt D-meson R_pPb integrated over p_T is compatible with unity and with model calculations implementing modification of the parton distribution functions of nucleons bound in nuclei with respect to free nucleons. The non-prompt Λc+/D⁰ and D⁺/D⁰ production ratios are computed to investigate hadronisation mechanisms of beauty quarks into mesons and baryons. The measured ratios as a function of p_T display a similar trend to that measured for charm hadrons in the same collision system.