Speaker
Rajesh Sangem
(IIT Bombay)
Description
Among the leading twist gluon TMDs, gluon Sivers function (GSF) and Boer-Mulders function (BMF) have been receiving paramount of interest in spin physics, as they provide the spin nature of the hadron. The GSF and BMF describe the density of unpolarized and linearly polarized gluons inside the transversely and unpolarized proton respectively. The non-perturbative GSF and BMF can be extracted by studying the Sivers and $\cos2\phi$ asymmetries in $ep$ and $pp$ collision. We estimate the Sivers and $\cos2\phi$ asymmetries in $J/\psi$ production in SIDIS process within TMD factorization framework. The leading order photon-gluon fusion subprocess color octet sates ${^3}{S}{_1}$, ${^1}{S}{_0}$ and ${^3}{P}{_J}$ ($J=0,1,2$) contribution to $J/\psi$ production is considered by employing the NRQCD based color octet model. The estimated negative Sivers asymmetry is in good agreement with COMPASS data at $z=1$. Sizable $\cos2\phi$ asymmetry is estimated as a function of Bjorken variable ($x_B$) and $p_T$. We also calculate the Sivers asymmetry in photoproduction of $J/\psi$ at Next-Leading-Order in $\alpha_s$ using color octet model.
Primary author
Rajesh Sangem
(IIT Bombay)
Co-author
Asmita Mukherjee
(Physics Department, IIT Bombay)
