The $\sin2\phi$ azimuthal asymmetry in single longitudinally polarized $\pi N$ Drell-Yan process

TL;DR

This paper investigates the $ ext{sin}2 heta$ azimuthal asymmetry in the single longitudinally polarized $ ext{π}N$ Drell-Yan process, revealing insights into 3D parton distributions and the nucleon's chiral-odd structure.

Contribution

It introduces a calculation of the $ ext{sin}2 heta$ asymmetry using spectator models for Boer-Mulders and transversity functions, providing new understanding of nucleon structure.

Findings

Calculated asymmetries for $ ext{π}^ ext{±}$ beams on proton and deuteron targets.

Demonstrated the potential to probe 3D parton distributions.

Highlighted the connection to the chiral-odd structure of the nucleon.

Abstract

We study the $\sin2\phi$ azimuthal asymmetry in the $\pi N$ Drell-Yan process, when the nucleon is longitudinally polarized. The asymmetry is contributed by the combination of the Boer-Mulders function and the longitudinal transversity distribution function. We consider the Drell-Yan processes by $\pi^\pm$ beams colliding on the proton and deuteron targets, respectively. We calculate the $\sin2\phi$ azimuthal asymmetries in these processes using the Boer-Mulders function and the longitudinal transversity from spectator models. We show that the study on single polarized $\pi N$ Drell-Yan processes can not only give the information on the new 3-dimensional parton distribution functions in momentum space, but also shed light on the chiral-odd structure of the longitudinally polarized nucleon.