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)
