Fragmentation contributions to $J/\psi$ photoproduction at HERA

Abstract

We compute leading-power fragmentation corrections to $J/\psi$ photoproduction at DESY HERA, making use of the nonrelativistic QCD factorization approach. Our calculations include parton production cross sections through order ${\alpha }_s^3$, fragmentation functions though order ${\alpha }_s^2$, and leading logarithms of the transverse momentum divided by the charm-quark mass to all orders in ${\alpha }_s$. We find that the leading-power fragmentation corrections, beyond those that are included through next-to-leading order in ${\alpha }_s$, are small relative to the fixed-order contributions through next-to-leading order in ${\alpha }_s$. Consequently, an important discrepancy remains between the experimental measurements of the $J/\psi$ photoproduction cross section and predictions that make use of nonrelativistic-QCD long-distance matrix elements that are extracted from the $J/\psi$ hadroproduction cross-section and polarization data.

16 pages, 6 figures, minor revisions, version published in Phys. Rev. D

References in corpus (8)

• J/psi (psi') production at the Tevatron and LHC at O(α_s^4v^4) in nonrelativistic QCD
• Reconciling J/psi production at HERA, RHIC, Tevatron, and LHC with NRQCD factorization at next-to-leading order
• Polarization for Prompt J/psi, psi(2s) production at the Tevatron and LHC
• Improved determination of color-singlet nonrelativistic QCD matrix elements for S-wave charmonium
• Quarkonium production in the LHC era: a polarized perspective
• Next-to-leading-order tests of nonrelativistic-QCD factorization with $J/\psi$ yield and polarization
• Quark fragmentation into spin-triplet $S$-wave quarkonium
• Fragmentation functions of polarized heavy quarkonium

Cited by in corpus (7)

• Fragmentation contributions to hadroproduction of prompt $J/\psi$, ${\chi }_{cJ}$, and $\psi (2S)$ states
• Inclusive production of $J/\psi$, $\psi (2S)$, and ${\rm Y}$ states in pNRQCD
• Heavy quarkonium photoproduction in ultrarelativistic heavy ion collisions
• Production and polarization of $S$-wave quarkonia in potential nonrelativistic QCD
• QCD leading order study of the $J/\psi$ leptoproduction at HERA within the nonrelativistic QCD framework
• Statistical analysis of the azimuthal asymmetry in the $J/\psi$ leptoproduction in unpolarized $ep$ collisions
• Kinematic distributions of the ${\eta }_c$ photoproduction in $ep$ collisions within the nonrelativistic QCD framework