On new $k_\perp$-dependent (quasi)parton distribution functions

TL;DR

This paper proposes a new class of $k_ot$-dependent parton distribution functions that relate to quark spin alignment and transverse motion, expanding the understanding of parton dynamics inside hadrons.

Contribution

It introduces a novel type of $k_ot$-dependent functions associated with quark spin alignment, distinct from the Boer-Mulders function, and links them to parton transverse motion and interactions.

Findings

New $k_ot$-dependent functions linked to quark spin alignment.

These functions are sensitive to parton transverse motion.

They are initiated by specific interaction correlators.

Abstract

We advocate the existence of a new type of $k_\perp$-dependent functions. In contrast to the well-known Boer-Mulders function, the presented new functions can be associated with the collective alignment of quark spin vectors. Moreover, the new functions are sensitive to the transverse motion of partons inside hadrons, which are linked to the spin alignment of partons, and they are initiated by the interactions encoded in the corresponding correlators.