title: Factorized power expansion for high-pT heavy quarkonium production.
abstract: We show that when the factorized cross section for heavy quarkonium production includes next-to-leading power contributions associated with the production of the heavy quark pair at short distances, it naturally reproduces all high p(T) results calculated in nonrelativistic QCD (NRQCD) factorization. This extended formalism requires fragmentation functions for heavy quark pairs, as well as for light partons. When these fragmentation functions are themselves calculated using NRQCD, we find that two of the four leading NRQCD production channels, (3)S(1)([1]) and (1)S(0)([8]), are dominated by the next-to-leading power contributions for a very wide p(T) range. The large next-to-leading order corrections of NRQCD are absorbed into the leading order of the first power correction. The impact of this finding on heavy quarkonium production and its polarization is discussed.
authors.affiliation: Physics Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA.
authors.forename: Yan-Qing
authors.initials: YQ
authors.lastname: Ma
authors.affiliation: Physics Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA and C.N. Yang Institute for Theoretical Physics, Stony Brook University, Stony Brook, New York 11794-3840, USA and Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA.
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Qiu
authors.affiliation: C.N. Yang Institute for Theoretical Physics, Stony Brook University, Stony Brook, New York 11794-3840, USA and Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA.
authors.forename: George
authors.initials: G
authors.lastname: Sterman
authors.affiliation: Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang