Probing transverse momentum dependent gluon distribution functions from hadronic quarkonium pair production

Abstract

The inclusive hadronic production of ${\eta }_Q$(${\eta }_c$ or ${\eta }_b$) pair is proposed to extract the transverse momentum dependent(TMD) gluon distribution functions. We use nonrelativistic QCD(NRQCD) for the production of ${\eta }_Q$. Under nonrelativistic limit TMD factorization for this process is assumed to make a lowest order calculation. For unpolarized initial hadrons, unpolarized and linearly polarized gluon distributions can be extracted by studying different angular distributions.

Comments: 7 pages, 3 figures, 1 table