J/psi polarization in photoproduction up to the next-to-leading order of QCD
J/psi polarization in photoproduction up to the next-to-leading order of QCD
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DOI：
10.1103/physrevd.80.034020
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发表时间：
2009-01
影响因子：
5
通讯作者：
Chao-Hsi Chang;Rong Li;Jian-xiong Wang
中科院分区：
文献类型：
--
作者：
Chao-Hsi Chang;Rong Li;Jian-xiong Wang
我们研究了强子电子环加速器（HERA）光生过程中的J/psi极化，直到QCD的次领先阶。结果表明，J/psi产生物的横动量p（t）和能分率z分布与观测值不太一致。对于重正化和因子化尺度的各种选择，J/psi极化参数的z分布的理论不确定性太大，无法给出明确的预测。当p（t）> 3GeV时，这些参数的p（t）分布的不确定性很小，即使在这个区域，所得的p（t）分布也不能描述实验数据。
We investigate the J/psi polarization in photoproduction at the Hadron Electron Ring Accelerator (HERA) up to the next-to-leading order of QCD. The results show that the transverse momentum p(t) and energy fraction z distributions of J/psi production do not agree with the observed ones very well. The theoretical uncertainties for the z distributions of the J/psi polarization parameters with respect to various choices of the renormalization and factorization scales are too large to give a definite predication. The uncertainties for the p(t) distributions of these parameters are small when p(t) > 3 GeV and the obtained p(t) distributions cannot describe the experimental data even in this region.