QCD corrections to e+e- -->J/psi+gg at B factories.
In heavy quarkonium production, the measured ratio R_{cc[over ]}=sigma[J/psi+cc[over ]+X]/sigma[J/psi+X] at B factories is much larger than existing theoretical predictions. To clarify this discrepancy, in nonrelativistic QCD we find the next-to-leading-order (NLO) QCD correction to e;{+}e;{-}-->J/psi+gg can enhance the cross section by about 20%. Together with the calculated NLO result for e;{+}e;{-}-->J/psi+cc[over ], we show that the NLO corrections can significantly improve the fit to the ratio R_{cc[over ]}. The effects of leading logarithm resummation near the end point on the J/psi momentum distribution and total cross section are also considered. Comparison of the calculated cross section for e;{+}e;{-}-->J/psi+gg with the observed cross section for e;{+}e;{-}-->J/psi+non-(cc[over ]) is expected to provide unique information on the issue of color-octet contributions.
Ma
Yan-Qing
YQ
Department of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China.
Zhang
Yu-Jie
YJ
Chao
Kuang-Ta
KT