Resummation of large endpoint corrections to color-octet J/ψ photoproduction

Journal Article (Journal Article)

An unresolved problem in J/ψ phenomenology is a systematic understanding of the differential photoproduction cross section, dσ/dz[γ+p→J/ψ+X], where z=Eψ/Eγ in the proton rest frame. In the nonrelativistic QCD (NRQCD) factorization formalism, fixed-order perturbative calculations of color-octet mechanisms suffer from large perturbative and nonperturbative corrections that grow rapidly in the endpoint region, z→1. In this paper, NRQCD and soft collinear effective theory are combined to resum these large corrections to the color-octet photoproduction cross section. We derive a factorization theorem for the endpoint differential cross section involving the parton distribution function and the color-octet J/ψ shape functions. A one-loop matching calculation explicitly confirms our factorization theorem at next-to-leading order. Large perturbative corrections are resummed using the renormalization group. The calculation of the color-octet contribution to dσ/dz is in qualitative agreement with data. Quantitative tests of the universality of color-octet matrix elements require improved knowledge of shape functions entering these calculations as well as resummation of the color-singlet contribution which accounts for much of the total cross section and also peaks near the endpoint. © 2006 The American Physical Society.

Full Text

Duke Authors

Cited Authors

  • Fleming, S; Leibovich, AK; Mehen, T

Published Date

  • December 14, 2006

Published In

Volume / Issue

  • 74 / 11

Electronic International Standard Serial Number (EISSN)

  • 1550-2368

International Standard Serial Number (ISSN)

  • 1550-7998

Digital Object Identifier (DOI)

  • 10.1103/PhysRevD.74.114004

Citation Source

  • Scopus