在B工厂中，考虑次领头阶量子色动力学修正的情况下，正负电子对撞产生双粲夸克过程e+e- -->J/psi + cc 。
Double-charm production e+e- -->J/psi + cc at B factories with next-to-leading-order QCD corrections.
作者信息
Zhang Yu-Jie, Chao Kuang-Ta
机构信息
Department of Physics, Peking University, Beijing 100871, People's Republic of China.
出版信息
Phys Rev Lett. 2007 Mar 2;98(9):092003. doi: 10.1103/PhysRevLett.98.092003.
The inclusive J/psi production in e;{+}e;{-}-->J/psicc at B factories is one of the most challenging open problems in heavy quarkonium physics. The observed cross section of this double-charm production process is larger than existing leading order (LO) QCD predictions by a factor of 5. In the nonrelativistic QCD (NRQCD) factorization formalism, we calculate the next-to-leading order (NLO) QCD virtual and real corrections to this process, and find that these corrections can substantially enhance the cross section with a K factor of about 1.8. We further take into account the feeddown contributions from higher charmonium states [mainly the psi(2S) as well as chi_{cJ}] and the two-photon contributions, and find that the discrepancy between theory and experiment can be largely removed.
在B工厂中，通过(e^{+}e^{-}\to J/\psi c\overline{c})过程产生的包容性(J/\psi)是重夸克偶素物理中最具挑战性的开放性问题之一。这个双粲夸克产生过程的观测截面比现有的领头阶（LO）量子色动力学（QCD）预测值大5倍。在非相对论性QCD（NRQCD）因子化形式体系中，我们计算了该过程的次领头阶（NLO）QCD虚修正和实修正，发现这些修正能够以约1.8的K因子大幅提高截面。我们进一步考虑了来自更高粲夸克偶素态（主要是(\psi(2S))以及(\chi_{cJ})）的压低贡献和双光子贡献，发现理论与实验之间的差异可以在很大程度上消除。
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