Energy dependence of the Cronin effect from nonlinear QCD evolution.
The nonlinear evolution of dense partonic systems has been suggested as a novel physics mechanism relevant for the dynamics of p-A and A-A collisions at collider energies. Here we study to what extent the description of Cronin enhancement in the framework of this nonlinear evolution is consistent with the recent observation in sqrt[s]=200 GeV d-Au collisions at the Relativistic Heavy Ion Collider. We solve the Balitsky-Kovchegov evolution equation numerically for several initial conditions encoding Cronin enhancement. We find that the properly normalized nuclear gluon distribution is suppressed at all momenta relative to that of a single nucleon. For the resulting spectrum of produced gluons in p-A and A-A collisions, the nonlinear QCD evolution is unable to generate a Cronin-type enhancement, and it quickly erases any such enhancement which may be present at lower energies.
Departamento de Física, Universidad de Córdoba, 14071 Córdoba, Spain.
Javier L
JL
Albacete
Néstor
N
Armesto
Alex
A
Kovner
Carlos A
CA
Salgado
Urs Achim
UA
Wiedemann