We estimate Sivers asymmetry in low virtuality photoproduction of J/ψ using color evaporation model and taking into account Q2- evolution of transverse momentum dependent PDF's and Sivers function. There is a substantial reduction in asymmetry as compared to our previous analysis wherein the Q2-dependance came only from DGLAP evolution of collinear part of TMDs. The estimates of asymmetry are comparable to our earlier estimates in which we had used analytical solution of only an approximated form of the evolution equations. We have also estimated asymmetry using the latest parametrization by Echevarria {\it et al.} which are based on an evolution kernel in which the perturbative part is resummed to NLL accuracy.
@article{arxiv.1411.0832,
title = {SSA in electroproduction of $J/\psi$ and QCD-evolved TMD's},
author = {Rohini M. Godbole and Abhiram Kaushik and Anuradha Misra and Vaibhav S. Rawoot},
journal= {arXiv preprint arXiv:1411.0832},
year = {2015}
}
Comments
Conference proceedings of QCD Evolution Workshop 2014