title: Universality in the nuclear dependence coefficient alpha(q(T))
abstract: We derive the nuclear dependence coefficient alpha(q(T)) for Drell-Yan and J/psi production. We show that at small q(T), alpha(q(T)) is given by a universal functional form: alpha(q(T)) = a+bq(2)(T), and the parameters a and b are completely determined by either perturbatively calculable or independently measurable quantities. This universal functional form alpha(q(T)) is insensitive to A, and is consistent with existing data.
authors.affiliation: Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506, USA.
authors.initials: X
authors.lastname: Guo
authors.initials: J
authors.lastname: Qiu
authors.initials: X
authors.lastname: Zhang