# Predicting the light-front holographic TMDs of the pion

## TL;DR

This paper predicts the pion's twist-2 TMDs, including the unpolarized and Boer-Mulders functions, using a holographic light-front approach with non-perturbative gluon rescattering, aligning well with lattice data.

## Contribution

It introduces a holographic light-front model incorporating dynamical spin effects and non-perturbative SU(3) gluon rescattering to predict pion TMDs.

## Key findings

- Non-zero Boer-Mulders function predicted with spin effects and gluon rescattering.
- Non-perturbative color dynamics better match lattice data.
- Goes beyond perturbative U(1) approximation for gluon interactions.

## Abstract

We predict the twist-2 Transverse Momentum Dependent parton distribution functions (TMDs) of the pion, namely the unpolarized quark TMD, $f_{1}(x, k_\perp)$, and the transversely polarized quark TMD, also known as the Boer-Mulders function, $h^\perp_{1}(x, k_\perp)$, using a holographic light-front pion wavefunction with dynamical spin effects. These spin effects, in conjunction with gluon rescattering, are crucial to predict a non-zero holographic Boer-Mulders function. We investigate the use of a non-perturbative SU(3) gluon rescattering kernel, thus going beyond the usual approximation of perturbative U(1) gluons. We find that the non-perturbative color dynamics offer a more promising way to describe the available lattice data on the generalized Boer-Mulders shifts.