The polarized TMDs in the covariant parton model approach

TL;DR

This paper derives relations between polarized TMDs and PDFs within a covariant parton model, predicting the detailed momentum dependence of polarized TMDs based on known PDFs, under Lorentz invariance and rotational symmetry assumptions.

Contribution

It introduces a covariant approach linking polarized TMDs to PDFs, providing predictions for TMDs' momentum dependence from known PDFs.

Findings

Predicted x- and p_T-dependence of polarized TMDs.

Derived relations between TMDs and PDFs based on Lorentz invariance.

Established a covariant framework for polarized TMDs.

Abstract

We derive relations between polarized transverse momentum dependent distribution functions (TMDs) and the usual parton distribution functions (PDFs) in the 3D covariant parton model, which follow from Lorentz invariance and the assumption of a rotationally symmetric distribution of parton momenta in the nucleon rest frame. Using the known PDF $g_{1}^{q}(x)$ as input we predict the $x$- and $\mathbf{p}_{T}$-dependence of all polarized twist-2 naively time-reversal even (T-even) TMDs.