Quark Transverse Spin-Momentum Correlation of the Pion from Lattice QCD: The Boer-Mulders Function

TL;DR

This study presents the first lattice QCD calculation of the pion's Boer-Mulders function, revealing insights into the quark transverse spin-momentum correlation using advanced theoretical and computational techniques.

Contribution

It introduces a novel lattice QCD approach to compute the pion's Boer-Mulders function, incorporating state-of-the-art renormalization, perturbative matching, and continuum extrapolation.

Findings

First lattice QCD calculation of the pion's Boer-Mulders function.

Results provide key input for phenomenological models of spin asymmetries.

Achieved continuum and infinite momentum limit extrapolations.

Abstract

We present the first lattice QCD calculation of the quark transverse spin-momentum correlation, i.e., the T-odd Boer-Mulders function, of the pion, using large-momentum effective theory (LaMET). The calculation is done at three lattice spacings $a=(0.098, 0.085, 0.064)$ fm and pion masses $\sim350$ MeV, with pion momenta up to $1.8$ GeV. The matrix elements are renormalized in a state-of-the-art scheme and extrapolated to the continuum and infinite momentum limit. We have implemented the perturbative matching up to the next-to-next-to-leading order and carried out a renormalization-group resummation. Our results provide valuable input for phenomenological analyses of the Boer-Mulders single-spin asymmetry.