Speaker
Description
Recent measurements of charm-baryon production at midrapidity in small collision systems show a baryon-to-meson ratio significantly higher than that measured in e+e- and e-p collisions. These results indicate that the charm-baryon production in hadronic collisions is not fully understood and suggest a non-universality of fragmentation functions among different collision systems. Models that better describe the $\Lambda_\mathrm{c}^{+}/\mathrm{D}^{0}$ ratio in pp collisions point to a significant contribution to $\Lambda_\mathrm{c}^{+}$ yield from decays of heavier charm-baryon states. Therefore, measurements of the production of charm-baryon states decaying to $\Lambda_\mathrm{c}^{+}$ are crucial to understand the charm-quark hadronization in the presence of a surrounding partonic environment.
In this contribution, the measurements of $\Sigma_{\mathrm{c}}(2455)^{0,++}$ and $\Sigma_{\mathrm{c}}^{*}(2520)^{0,++}$ production in pp collisions at midrapidity obtained from the anlysis of the large datasets collected by ALICE during LHC Run 3 are presented. The classification of prompt and non-prompt $\Sigma_\mathrm{c}^{0,++}$ baryons is performed by exploiting machine-learning techniques, taking advantage of the excellent tracking and vertexing performance of the upgraded ALICE detectors. The baryon-to-baryon ratio $\Sigma_{\mathrm{c}}^{*}(2520)^{0,++}/\Sigma_{\mathrm{c}}(2455)^{0,++}$ is presented and compared with model predictions. The baryon-to-meson ratios $\Sigma_\mathrm{c}^{0,++,+++}/\mathrm{D}^{0}$ and the feed-down contribution to $\Lambda_\mathrm{c}^{+}$ production from $\Sigma_\mathrm{c}^{0,++,+++}$ are also reported, with a more detailed $p_{\mathrm{T}}$-differential study compared to Run 2 measurements. These measurements provide important constraints on the hadronization models and represent a fundamental contribution for the comprehension of charm quark hadronization.
