Speaker
Description
Produced mainly in hard-scattering processes occurring in the initial stage of the collisions, heavy quarks offer a unique perspective to study quark fragmentation and hadronisation. The ALICE experiment at the LHC has performed several measurements in proton--proton collisions of the transverse-momentum ($p_\mathrm{T}$)-differential cross section of charm and beauty mesons and baryons and of the properties of the jets containing them. While prompt and non-prompt D-meson cross sections are well reproduced by theoretical models using fragmentation functions tuned on $\mathrm{e^{+}e^{-}}$-collision data, a large excess of $\mathrm{\Lambda_{\rm c}^{+}}$, $\mathrm{\Xi_{\rm c}^{0,+}}$, $\mathrm{ \Sigma_{\rm c}^{0,++}}$, $\mathrm{\Omega_{\rm c}^{0}}$, and non-prompt $\mathrm{\Lambda_{\rm c}^{+}}$ baryon production was found up to $p_\mathrm{T}\approx 10-20$ $\mathrm{{GeV}}/c$.
The effect, which was investigated also as a function of multiplicity, evidences a dependence of hadronisation on the collision system and questions the validity of the assumption of fragmentation universality, at least of its late non-perturbative phase, suggesting that other concurrent processes are relevant in hadronic collisions. Further information and constraints on the description of fragmentation in Monte Carlo event generators are provided by the measurements of the fraction of jet-momentum carried by D mesons and $\mathrm{\Lambda_{\rm c}^{+}}$, as well as by the study of the azimuthal correlations of charm hadrons with light particles.
In this talk, an overview of the main measurements related to heavy-quark fragmentation will be given. Comparison with light-flavour hadron results will be discussed when relevant.