Eur. Phys. J. C (2008) 55: 449-461
https://doi.org/10.1140/epjc/s10052-008-0604-8

Regular Article - Theoretical Physics

A systematic study of J/ψ suppression in cold nuclear matter

¹ PH Department, TH Division, CERN, 1211, Geneva 23, Switzerland
² Laboratoire d’Annecy-le-Vieux de Physique Théorique (LAPTH), UMR 5108 du CNRS associée à l’Université de Savoie, B.P. 110, 74941, Annecy-le-Vieux Cedex, France
³ Laboratoire Leprince-Ringuet, Ecole Polytechnique, 91128, Palaiseau Cedex, France
⁴ Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA

^* e-mail: arleo@cern.ch

Received: 19 February 2007
Revised: 29 February 2008
Published online: 14 May 2008

Abstract

Understanding the effects of cold nuclear matter on J/ψ production is a key requirement for interpreting the J/ψ suppression reported in heavy-ion collisions. Based on a Glauber model, the J/ψ–nucleon inelastic cross section is determined from a statistical analysis of the J/ψ world data on nuclear targets. The global fit of all data gives σ_J/ψN = 3.4 ± 0.2 mb, significantly smaller than previous estimates, yet the χ² of the fit is pretty large, χ²/ndf=1.5. A similar value, σ_J/ψN = 3.5 ± 0.2 ± 1.7 mb, is obtained when the De Florian–Sassot modifications of the nuclear parton densities are included in the analysis, although we emphasise that the present uncertainties on gluon (anti-) shadowing do not allow for a precise determination of σ_J/ψN. Finally, the possible energy dependence of the J/ψ–nucleon inelastic cross section is investigated within this framework. No significant energy dependence of the J/ψ–N interaction is observed.