论文标题
Gluon Sivers的过程依赖性在$ p^\ uparrow p \ to j/ψ+ x $中在NRQCD中的TMD方法中
Process dependence of the gluon Sivers function in $p^\uparrow p \to J/ψ+ X$ within a TMD approach in NRQCD
论文作者
论文摘要
我们认为，在非权利性QCD中，在$ p^\ uparrow p \ $ p^\ uparrow p \ to j/ψ+ x $中，以$ j/ψ$生产为$ j/ψ$生产的横向单旋不对称（SSA）。扩展了先前的研究[1]，我们在这里采用了色谱不变的普通Parton模型（CGI-GPM），其中考虑了自旋和固有的横向动量效应，并考虑了前列初始和最终状态相互作用（ISIS和FSIS）。我们发现，即使在颜色颜色状态下产生重Quark对，ISIS和FSIS也会导致不变的SSA，从原则上允许测试Gluon Sivers功能（GSF）的过程依赖性。我们显示，由于所谓的$ f $ - 和$ d $ -Type GSFS出现在CGI-GPM中，这两个独立贡献中，$ d $ type type type被动态抑制了。因此，正如已经发现的$ j/ψ$编队的色彩单元模型方法[2]一样，只有$ f $ -type GSF可以在现象学中发挥作用。还与在不包含ISIS和FSI的普通Parton模型中获得的相应结果进行了比较。
We consider the transverse single-spin asymmetry (SSA) for $J/ψ$ production in $p^\uparrow p \to J/ψ+ X$ within a TMD approach in non-relativistic QCD. Extending a previous study [1], we employ here the color-gauge invariant generalized parton model (CGI-GPM), in which spin and intrinsic transverse momentum effects are taken into account, together with leading-order initial- and final-state interactions (ISIs and FSIs). We find that, even when the heavy-quark pair is produced in a color-octet state, ISIs and FSIs lead to a nonvanishing SSA, allowing, in principle, to test the process dependence of the gluon Sivers function (GSF). We show that of the two independent contributions, due to the so-called $f$- and $d$-type GSFs, appearing in the CGI-GPM, the $d$-type one turns out to be dynamically suppressed. Therefore, as already found adopting the Color-Singlet Model approach for the $J/ψ$ formation [2], only the $f$-type GSF could play a role in phenomenology. A comparison with the corresponding results obtained in the generalized parton model, without the inclusion of ISIs and FSIs, is also carried out.
