Measurements of charm production in pp collisions with ALICE

TL;DR

This paper reports measurements of charm-hadron production in proton-proton collisions at 5.02 and 13 TeV using ALICE, revealing non-universal charm fragmentation and baryon-to-meson ratios dependent on collision systems.

Contribution

It provides new experimental data on charm production in pp collisions, challenging existing hadronisation models and highlighting the system dependence of charm fragmentation.

Findings

Baryon-to-meson ratios differ from e+e- and ep collision predictions.

Charm fragmentation fractions are not universal across collision systems.

Results show discrepancies with Monte Carlo and theoretical models.

Abstract

The production of charm-hadrons at midrapidity in pp collisions at $\sqrt{s}$ = 5.02 and 13 TeV was recently measured by the ALICE Collaboration. The results show that the baryon-to-meson yield ratios differ from predictions where the hadronisation has been tuned to measurements obtained in $\rm e^{+}e^{-}$ and ep collisions for different charm-baryon species. These observations suggest that the charm fragmentation fractions are not universal and that the baryon-to-meson ratio depends on the collision systems. The results are compared to the predictions from Monte Carlo event generators and theoretical calculations.