Speaker
Description
Quarkonium production in high-energy proton-proton (pp) collisions provides a unique probe of both perturbative and non-perturbative aspects of quantum chromodynamics (QCD). Charmonium states, such as the J/ψ and ψ(2S), are produced through a two-stage process involving hard parton-parton scatterings followed by non-perturbative hadronization. Precise measurements are essential to constrain theoretical models and improve our understanding of these mechanisms. In this presentation, preliminary results on the J/ψ production cross section at √s = 13.6 TeV, measured by ALICE, will be shown. Thanks to the new Muon Forward Tracker (MFT), the separation of prompt and non-prompt J/ψ production is now possible at forward rapidity (2.5 < y < 3.6), and first measurements of their relative contributions will be presented. Additionally, the dependence of inclusive J/ψ yields on the relative charged-particle multiplicity, measured at √s = 13 TeV in the pseudorapidity range -3.7 < η < -1.7, will be discussed. The observed steeper-than-linear trend highlights the role of multi-parton interactions. Finally, the ψ(2S)-to-J/ψ double ratio and its comparison with model predictions provide further insight into the interplay between soft and hard processes in charmonium production.
