J/Psi production as a function of charged particle multiplicity in pp collisions at sqrt{s}=7 TeV with the ALICE experiment

TL;DR

This paper presents the first measurement of J/Psi meson production as a function of charged particle multiplicity in proton-proton collisions at 7 TeV, using the ALICE detector at the LHC, covering different rapidity ranges.

Contribution

It provides new experimental data on J/Psi production dependence on charged particle density at different rapidities in pp collisions at 7 TeV.

Findings

J/Psi production increases with charged particle multiplicity.

Results differ between mid-rapidity and forward rapidity.

Preliminary PYTHIA simulations are compared with measurements.

Abstract

We report on the first measurement of J/Psi production as a function of charged particle pseudo-rapidity density dN_ch/d_eta in pp collisions at sqrt{s} = 7 TeV with the ALICE experiment at the LHC. J/Psi mesons are detected down to p_T = 0 via their decays into e+e- pairs at mid-rapidity (|y| < 0.9) and into mu+mu- pairs at forward rapidity (2.5<y<4). dN_ch/d_eta is measured within |eta| < 1. We compare results in the two different J/Psi rapidity ranges. Preliminary PYTHIA simulations are also presented.