English

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

High Energy Physics - Phenomenology 2009-06-19 v2 High Energy Physics - Experiment

Abstract

In heavy quarkonium production, the measured ratio Rccˉ=σ[J/ψ+ccˉ+X]/σ[J/ψ+X]R_{c \bar c}=\sigma[J/\psi+ c\bar c + X]/\sigma[J/\psi +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+eJ/ψ+gge^+ e^- \to J/\psi +gg can enhance the cross section by about 20%. Together with the calculated NLO result for e+eJ/ψ+ccˉe^+ e^- \to J/\psi +c\bar c, we show that the NLO corrections can significantly improve the fit to the ratio RccˉR_{c \bar c}. The effects of leading logarithm resummation near the end point on the J/ψJ/\psi momentum distribution and total cross section are also considered. Comparison of the calculated cross section for e+eJ/ψ+gge^+ e^- \to J/\psi +gg with observed cross section for e+eJ/ψ+non(ccˉ)e^+ e^- \to J/\psi +non(c\bar c) is expected to provide unique information on the issue of color-octet contributions.

Keywords

Cite

@article{arxiv.0812.5106,
  title  = {QCD corrections to $\bm{e^+ e^- \to J/\psi g g}$ at B Factories},
  author = {Yan-Qing Ma and Yu-Jie Zhang and Kuang-Ta Chao},
  journal= {arXiv preprint arXiv:0812.5106},
  year   = {2009}
}

Comments

published version in PRL, 4 pages, 6 figures, references added, one figure changed