# QM 2011 - XXII International Conference on Ultrarelativistic Nucleus-Nucleus Collisions

May 22 – 28, 2011
Centre Bonlieu
Europe/Zurich timezone

## Measurement of the Multiplicity Dependence of J/ψ → e+e− Production in √s = 7 TeV pp Collisions with ALICE at the LHC

Not scheduled
Théâtre National (Centre Bonlieu)

### Théâtre National

#### Centre Bonlieu

France
Board: 76
Poster Heavy flavor and quarkonia production

### Speaker

Frederick Kramer (IKF, Goethe-Universität Frankfurt)

### Description

ALICE is the dedicated heavy-ion physics experiment at the Large Hadron Collider (LHC). It is designed to provide excellent capabilities to study the Quark-Gluon Plasma (QGP), the deconfined state of strongly-interacting matter, in the highest energy density regime opened up by the LHC. Quarkonia, bound states of heavy (charm or bottom) quarks such as the J/ψ, are crucial probes of the QGP. Before drawing conclusions on QGP-induced phenomena all non-QGP effects influencing quarkonia yields have to be understood. ALICE has measured the charged particle multiplicity distribution at √s = 7 TeV pp collisions [1]. A good fraction of events feature multiplicities that are of the same order as in central heavy-ion collisions at SPS energies. Thus, final-state effects present in heavy-ion collisions, such as a possible interaction with comovers [2], might be unveiled at LHC energies studying the multiplicity dependence of J/ψ production in pp collisions. We will present first results of the multiplicity dependence of J/ψ production in √s = 7 TeV pp collisions. The analysis is based on the reconstruction of the channel J/ψ→e+e− using the central barrel detectors of ALICE. References [1] K. Aamodt et al., “Charged-particle multiplicity measurement in proton-proton collisions at √s = 7 TeV with ALICE at LHC”, EPJ C 68 (2010) 345. [2] A. Capella et al., “J/ψ suppression at √s = 200 GeV in the comovers interaction model”, EPJ C 42 (2005) 419.

### Primary author

Frederick Kramer (IKF, Goethe-Universität Frankfurt)

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