Speakers
Description
The production cross sections of open heavy-flavour hadrons in pp and p-Pb collisions are typically described within the factorisation approach as the convolution of the parton distribution functions of the incoming protons, the perturbative QCD partonic cross section, and the fragmentation functions. The latter are typically parametrised from measurements in ${\rm e^+e^-}$ collisions, assuming universality across different collision systems. Measurements of charm baryon and meson production in pp and p-Pb collisions, and measurements of their yield production as a function of multiplicity, help to investigate hadronization processes and to study how these processes are modified across systems, from pp to Pb-Pb and from low to high multiplicities.
In this poster, the latest measurements of $\Lambda^+_{\rm c}$ down to $p_{\rm T}=0$, performed with the ALICE detector at midrapidity in pp and p–Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV, are presented. This is the first ALICE measurement, down to $p_{\rm T}=0$, of the $\Lambda^+_{\rm c}/{\rm D^0}$ ratio in pp and p–Pb collisions. This result, together with the already published measurement of the cross section for the ${\rm D^0}$, ${\rm D^+}$, ${\rm D^+_{\rm s}}$ and ${\rm \Xi^0_{\rm c}}$ production, allows an evaluation of the total section and fragmentation fractions. The result unambiguously shows that the charm fragmentation is not universal across leptonic and hadronic collision systems. The $\Lambda^+_{\rm c}/{\rm D^0}$ yield ratios as measured as a function of charged particle multiplicity in pp and p-Pb collisions is also shown and compared to different hadronization models.
