Forward rapidity $\psi(\mathrm{2S})$ meson production in pp, p-Pb and Pb-Pb collisions with ALICE at the LHC

TL;DR

This paper reports on the measurement of $ ext{psi(2S)}$ meson production in proton-proton, proton-lead, and lead-lead collisions at the LHC, revealing suppression patterns and challenging existing theoretical models.

Contribution

It provides new experimental data on $ ext{psi(2S)}$ production across different collision systems and compares these to J/$ ext{psi}$ results, highlighting discrepancies with current models.

Findings

$ ext{psi(2S)}$ suppression in p-Pb collisions compared to J/$ ext{psi}$.

Discrepancies between observed suppression and cold nuclear matter effect models.

Preliminary $ ext{psi(2S)}$ production results in Pb-Pb collisions as a function of centrality.

Abstract

The ALICE Collaboration has studied the inclusive $\psi(\mathrm{2S})$ meson production in pp, p-Pb and Pb-Pb collisions at the CERN LHC. The $\psi(\mathrm{2S})$ is detected through its decay to a muon pair, using the forward Muon Spectrometer, which covers the pseudo-rapidity range $-4<\eta<-2.5$. The $\psi(\mathrm{2S})$ production cross sections in pp collisions are presented as a function of rapidity (y) and transverse momentum ($p_{\mathrm{T}}$). In p-Pb collisions, $\psi(\mathrm{2S})$ results are compared to the J/$\psi$ ones by the ratio of their production cross sections as a function of rapidity, transverse momentum and event activity. The $\psi(\mathrm{2S})$ nuclear modification factor, $R_{\mathrm{pA}}$, is also discussed. The results show a $\psi(\mathrm{2S})$ suppression compared to the one observed for the J/$\psi$ meson and are not described by theoretical models including cold nuclear matter effects as nuclear shadowing and energy loss. Finally, the preliminary results of $\psi(\mathrm{2S})$ meson production in Pb-Pb collisions are shown in two $p_{\mathrm{T}}$ ranges as a function of the collision centrality.