Inclusive quarkonium production at forward rapidity in pp collisions at $\sqrt{s}=8$ TeV

TL;DR

This paper measures the production rates of various quarkonium states in proton-proton collisions at 8 TeV using the ALICE detector, providing detailed cross sections over different transverse momentum and rapidity ranges.

Contribution

It presents the first comprehensive measurement of inclusive quarkonium production cross sections at forward rapidity in pp collisions at 8 TeV with the ALICE detector, including differential and integrated values.

Findings

Measured cross sections for J/ψ, ψ(2S), Υ(1S), Υ(2S), Υ(3S)

Results agree with LHCb measurements within 1.4σ

Provides data for testing QCD models of quarkonium production

Abstract

We report on the inclusive production cross sections of J/$\psi$, $\psi$(2S), $\Upsilon$(1S), $\Upsilon$(2S) and $\Upsilon$(3S), measured at forward rapidity with the ALICE detector in pp collisions at a center-of-mass energy $\sqrt{s}=8$ TeV. The analysis is based on data collected at the LHC and corresponds to an integrated luminosity of 1.28 pb$^{-1}$. Quarkonia are reconstructed in the dimuon-decay channel. The differential production cross sections are measured as a function of the transverse momentum $p_{\rm T}$ and rapidity $y$, over the $p_{\rm T}$ ranges $0<p_{\rm T}<20$ GeV/$c$ for J/$\psi$, $0<p_{\rm T}<12$ GeV/$c$ for all other resonances, and for $2.5<y<4$. The cross sections, integrated over $p_{\rm T}$ and $y$, and assuming unpolarized quarkonia, are $\sigma_{{\rm J}/\psi} = 8.98\pm0.04\pm0.82$ $\mu$b, $\sigma_{\psi{\rm (2S)}} = 1.23\pm0.08\pm0.22$ $\mu$b, $\sigma_{\Upsilon{\rm(1S)}} = 71\pm6\pm7$ nb, $\sigma_{\Upsilon{\rm(2S)}} = 26\pm5\pm4$ nb and $\sigma_{\Upsilon{\rm(3S)}} = 9\pm4\pm1$ nb, where the first uncertainty is statistical and the second one is systematic. These values agree, within at most $1.4\sigma$, with measurements performed by the LHCb collaboration in the same rapidity range.