Issue Eur. Phys. J. C Volume 62, Number 1, July 2009 Hot Quarks 2008 Page(s) 151 - 157 Section Regular Article - Theoretical Physics DOI 10.1140/epjc/s10052-009-0899-0 Published online 14 February 2009

Eur. Phys. J. C 62, 151-157 (2009)
DOI: 10.1140/epjc/s10052-009-0899-0

Jet multiplicity distributions: medium dependence in MLLA

Néstor Armesto, Carlos Pajares and Paloma Quiroga-Arias

Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706, Santiago de Compostela, Spain

pquiroga@fpaxp1.usc.es

Received 29 September 2008 / Published online 14 February 2009

Abstract

We study the medium dependence of the multiplicity distributions in the modified leading logarithmic approximation. We focus in the enhancement in the number of branchings as the partons travel trough a dense medium created in a heavy-ion collision. We study the effect of a higher number of splittings in some jet observables by introducing the medium as a constant (f _med) in the splitting functions. Having as our ansatz for the quark and gluon jets mean multiplicities 〈n _G 〉=e ^{γ y} and 〈n _Q 〉=r ⁻¹e ^{γ y} , we study in an analytic approach the dependence with the medium (f _med) of the anomalous dimension (γ), the multiplicity ratio (r), and so the mean multiplicities. We also obtain the higher-order moments of the multiplicity distribution, what allows us to study its dispersion.

Correspondence: pquiroga@fpaxp1.usc.es


© Società Italiana di Fisica, Springer-Verlag 2009

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