1307.1094 (ALICE Collaboration)

Multiplicity dependence of the average transverse momentum in pp, p-Pb,
and Pb-Pb collisions at the LHC    [PDF]

ALICE Collaboration

The average transverse momentum versus the charged-particle multiplicity N_ch was measured in p-Pb collisions at a collision energy per nucleon-nucleon pair sqrt(s_NN) = 5.02 TeV and in pp collisions at collision energies of sqrt(s) = 0.9, 2.76, and 7 Tev in the kinematic range 0.15 < p_T < 10.0 Gev/c and |eta| < 0.3 with the ALICE apparatus at the LHC. These data are compared to results in Pb-Pb collisions at sqrt(s_NN) = 2.76 Tev at similar charged-particle multiplicities. In pp and p-Pb collisions, a strong increase of with N_ch is observed, which is much stronger than that measured in Pb-Pb collisions. For pp collisions, this could be attributed, within a model of hadronizing strings, to multiple-parton interactions and to a final-state color reconnection mechanism. The data in p-Pb and Pb-Pb collisions cannot be described by an incoherent superposition of nucleon-nucleon collisions and pose a challenge to most of the event generators.

View original: http://arxiv.org/abs/1307.1094