Speaker
Description
Recent measurements of charm baryon production in pp and p-Pb collisions at LHC energies show a baryon-over-meson ratio significantly higher than expectations from Monte Carlo generators tuned to reproduce the lower values measured in ${\rm e}^{+}{\rm e}^{-}$ and ${\rm e}^{\pm}{\rm p}$ collisions. In Pb--Pb collisions at LHC and Au--Au collisions at RHIC, even higher values of $\Lambda_{\rm c}^{+}/{\rm D^{0}}$ ratios were observed, described within large uncertainties by models that foresee that $\Lambda_{\rm c}^{+}$ can form via coalescence of charm quarks with light quarks from the medium. These results indicate that charm baryon production in hadronic collisions is not fully understood and suggest that heavy-quark hadronisation can be sensitive to the presence of a surrounding hadronic environment.
Models that better reproduce the $\Lambda_{\rm c}^{+}/{\rm D^{0}}$ ratio in pp collisions expect a significant contribution to $\Lambda_{\rm c}^{+}$ yield from decays of heavier charm-baryon states, among which $\Sigma_{\rm c}$ states. The same models also predict an enhancement of $\Xi_{\rm c}/{\rm D^{0}}$ ratios with respect to ${\rm e}^{+}{\rm e}^{-}$ data. Therefore, the measurement of the production of $\Sigma_{\rm c}$ and $\Xi_{\rm c}$ states can provide fundamental insight into charm hadronisation.
In this contribution the prospects for measuring $\Xi_{\rm c}^{+}$ and $\Sigma_{\rm c}^{++,0}$ production at mid-rapidity with the ALICE detector via the reconstruction of the $\Xi_{\rm c}^{+}\rightarrow {\rm pK^{-}}\pi^{+}$ and $\Sigma_{\rm c}^{++,0}\rightarrow \Lambda_{\rm c}^{+}\pi^{+,-}, \Lambda_{\rm c}^{+}\rightarrow{\rm pK^{-}}\pi^{+}$ decay channels will be presented.
