Contributor info: Prof. Umberto D'Alesio

Umberto D'Alesio, Francesco Murgia, Marco Zaccheddu

SciPost Phys. Proc. 8, 131 (2022) · published 13 July 2022 | Toggle abstract · pdf

Experimental data from Belle Collaboration for the transverse polarization of $\Lambda$'s measured in $e^+ e^-$ annihilation processes are used to extract the polarizing fragmentation function (FF) within a TMD approach. We consider both associated and inclusive $\Lambda$ production, showing a quite consistent scenario. Good separation in flavor is obtained, leading to four independent FFs. Predictions for SIDIS processes at the EIC, crucial for understanding their universality and evolution properties, are also presented.

Carlo Flore, Maria Elena Boglione, Umberto D'Alesio, Josè Osvaldo Gonzalez-Hernandez, Francesco Murgia, Alexei Prokudin

SciPost Phys. Proc. 8, 034 (2022) · published 11 July 2022 | Toggle abstract · pdf

The Bayesian reweighting procedure is applied for the first time to a TMD distribution, the quark Sivers function extracted from SIDIS data. By exploiting the recent published single spin asymmetry data for the inclusive jet production in $p^\uparrow p$ collisions from the STAR collaboration at RHIC, we show how such a procedure allows to incorporate the information contained in the new data set, without the need of re-fitting, and to explore a much wider $x$ region compared to SIDIS measurements. The reweighting method is also extended to the case of asymmetric errors, and the results show a significant improvement on the knowledge of the quark Sivers function.

Sangem Rajesh, Umberto D'Alesio, Asmita Mukherjee, Francesco Murgia, Cristian Pisano

SciPost Phys. Proc. 8, 017 (2022) · published 11 July 2022 | Toggle abstract · pdf

We study the Sivers asymmetry in inelastic $J/\psi$ leptoproduction, $ep^\uparrow \to e+ J/\psi+X$, within a transverse momentum dependent scheme, the so-called generalized parton model (GPM). The effects of final-state interactions are properly taken into account by employing the color-gauge invariant GPM (CGI-GPM). For the $J/\psi$ formation the non-relativistic QCD (NRQCD) framework is adopted. Predictions for unpolarized cross sections and maximized Sivers asymmetries at EIC energies are given.