Eur. Phys. J. C (2013) 73: 2427
https://doi.org/10.1140/epjc/s10052-013-2427-5

Regular Article - Theoretical Physics

ϒ production in p(d)A collisions at RHIC and the LHC

¹ Departamento de Física de Partículas and IGFAE, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain
² Laboratoire Leprince Ringuet, École Polytechnique, CNRS/IN2P3, 91128, Palaiseau, France
³ IPNO, Université Paris-Sud, CNRS/IN2P3, 91406, Orsay, France
⁴ Service de Physique Nucléaire et Subnucléaire, Université de Mons, Place du Parc 20, 7000, Mons, Belgium
⁵ IRFU/SPhN, CEA Saclay, 91191, Gif-sur-Yvette Cedex, France

^* e-mail: lansberg@in2p3.fr

Received: 19 October 2012
Revised: 3 April 2013
Published online: 15 May 2013

Abstract

We study the effect of nuclear matter in ϒ production in dAu collisions at RHIC and pPb collisions at the LHC. We find that the nuclear modification factor, , measured at RHIC is not satisfactorily reproduced by the conventional effects used in the literature, namely the modification of the gluon distribution in bound nucleons and an—effective—survival probability for a bound state to escape the nucleus. In particular, we argue that this probability should be close to 1 as opposed to the J/ψ case. We note that, at backward rapidities, the unexpected suppression of observed by PHENIX hints at the presence of a gluon EMC effect, analogous to the quark EMC effect—but likely stronger. Further nuclear matter effects, such as saturation and fractional energy loss, are discussed, but none of them fit in a more global picture of quarkonium production. Predictions for ϒ(nS) for the forthcoming pPb run at 5 TeV at the LHC are also presented.