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arXiv · 0812.5106

QCD corrections to $\bm{e^+ e^- \to J/ψg g}$ at B Factories

Yan-Qing Ma·Yu-Jie Zhang·Kuang-Ta Chao
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Abstract

In heavy quarkonium production, the measured ratio $R_{c \bar c}=σ[J/ψ+ c\bar c + X]/σ[J/ψ+X]$ at B factories is much larger than existing theoretical predictions. To clarify this discrepancy, in nonrelativistic QCD (NRQCD) we find the next-to-leading-order (NLO) QCD correction to $e^+ e^- \to J/ψ+gg$ can enhance the cross section by about 20%. Together with the calculated NLO result for $e^+ e^- \to J/ψ+c\bar c$, we show that the NLO corrections can significantly improve the fit to the ratio $R_{c \bar c}$. The effects of leading logarithm resummation near the end point on the $J/ψ$ momentum distribution and total cross section are also considered. Comparison of the calculated cross section for $e^+ e^- \to J/ψ+gg$ with observed cross section for $e^+ e^- \to J/ψ+non(c\bar c)$ is expected to provide unique information on the issue of color-octet contributions.

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Yan-Qing Ma, Yu-Jie Zhang, Kuang-Ta Chao. 2009-04-24. QCD corrections to $\bm{e^+ e^- \to J/ψg g}$ at B Factories. https://doi.org/10.1103/physrevlett.102.162002

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