II. Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.
Phys Rev Lett. 2011 Jan 14;106(2):022003. doi: 10.1103/PhysRevLett.106.022003.
We calculate the cross section of inclusive direct J/ψ hadroproduction at next-to-leading order within the factorization formalism of nonrelativistic quantum chromodynamics, including the full relativistic corrections due to the intermediate 1S(0)[8], 3S(1)[8], and 3P(J)[8] color-octet states. We perform a combined fit of the color-octet long-distance matrix elements to the transverse-momentum (p(T)) distributions measured by CDF at the Fermilab Tevatron and H1 at DESY HERA and demonstrate that they also successfully describe the p(T) distributions from PHENIX at BNL RHIC and CMS at the CERN LHC as well as the photon-proton c.m. energy and (with worse agreement) the inelasticity distributions from H1. This provides a first rigorous test of nonrelativistic QCD factorization at next-to-leading order. In all experiments, the color-octet processes are shown to be indispensable.
我们在非相对论性量子色动力学的因子化形式主义内计算了领头阶下包含的 J/ψ 强子产生的截面,包括由于中间 1S(0)[8]、3S(1)[8]和 3P(J)[8]色八重态的完全相对论修正。我们对色八重态远程矩阵元进行了联合拟合,以拟合 CDF 在费米实验室 Tevatron 和 DESY HERA 的 H1 实验中测量的横动量(p(T))分布,并证明它们也成功地描述了 BNL RHIC 的 PHENIX、CERN LHC 的 CMS 以及 H1 的光子-质子质心能量和(一致性稍差)非弹性分布。这首次在领头阶下对非相对论性 QCD 因子化进行了严格检验。在所有实验中,色八重态过程被证明是不可或缺的。