2007/05/22 by Adam K. Leibovich, Adam K Leibovich, Xiaohui Liu
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1103/physrevd.76.034005
published as Phys.Rev.D76:034005,2007 · 17 pages, 7 figures
arxiv created 2007/05/22 · openalex publication_date 2007/08/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Recent observations of the J/\ensuremathψ spectrum produced in e+e^\ensuremath- collisions at the \ensuremathΥ(4S) resonance are in conflict with fixed-order calculations using the nonrelativsitic QCD effective theory (NRQCD). One problem is an enhancement in the cross section when the J/\ensuremathψ has maximal energy, due to large perturbative corrections (Sudakov logarithms). In a recent paper, the Sudakov logarithms in the color-octet contribution were summed by combining NRQCD with the soft-collinear effective theory. However, to be consistent, the color-singlet contributions must also be summed in the endpoint region which was not done in that paper. In this paper, we sum the leading logarithms in the color-singlet contribution to the J/\ensuremathψ production cross section. We find that the color-singlet cross section is suppressed near the endpoint compared to the fixed-order NRQCD prediction.