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arXiv · 0705.3230

The color-singlet contribution to e^+ e^- ->J/psi + X at the endpoint

Adam K Leibovich·Xiaohui Liu
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Abstract

Recent observations of the J/psi spectrum produced in e^+e^- collisions at the Upsilon(4S) resonance are in conflict with fixed-order calculations using Non-Relativsitic QCD effective theory (NRQCD). One problem is an enhancement in the cross section when the J/psi 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 and next-to-leading logarithms in the color-singlet contribution to the J/psi production cross section. We find that the color-singlet cross section is suppressed near endpoint compared to the fixed order NRQCD prediction.

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Adam K Leibovich, Xiaohui Liu. 2007-05-22. The color-singlet contribution to e^+ e^- ->J/psi + X at the endpoint. https://doi.org/10.1103/physrevd.76.034005

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