Leading twist T-even TMDs for the spin-1 heavy vector mesons

TL;DR

This paper investigates the leading twist T-even TMDs for spin-1 heavy vector mesons like J/ψ and Υ using light-front models and compares results with the Bethe-Salpeter approach, providing insights into their internal quark structure.

Contribution

It presents the first detailed calculation of TMDs for heavy vector mesons using light-front holographic and quark models, and compares these with Bethe-Salpeter results.

Findings

LFQM results agree with BSE model.

TMDs vary with quark momentum fraction and transverse momentum.

PDF predictions align with BLFQ and BSE models.

Abstract

We have presented the leading twist quark transverse momentum-dependent parton distribution functions (TMDs) for the spin-1 heavy vector mesons $J/\psi$-meson and $\Upsilon$-meson using the overlap of the light-front wave functions. We have computed their TMDs in the light-front holographic model (LFHM) as well as the light-front quark model (LFQM) and further compared the results with the Bethe-Salpeter (BSE) model. We have discussed the behavior of the TMDs with respect to momentum fraction carried by active quark ($x$) and the transverse quark momenta ($k_\perp$) in both the models. We have also calculated the $k_\perp$ moments of the quark in both the models and have compared the results with the BSE model. The predictions of LFQM are found to be in accord with the BSE model. Further, we have analyzed the leading twist parton distribution functions (PDFs) for both the heavy mesons in both the models and the results are found to be in accord with the basic light-front quantization (BLFQ) and BSE model.