Measurements of unpolarised azimuthal asymmetries at COMPASS

TL;DR

This paper reports measurements of azimuthal asymmetries in unpolarized semi-inclusive deep inelastic scattering at COMPASS, providing insights into quark transverse momentum and the Boer-Mulders function.

Contribution

First extraction of unpolarized azimuthal asymmetries for positive and negative hadrons at COMPASS, comparing results with theoretical models.

Findings

Asymmetries measured for positive and negative hadrons.

Results compared with theoretical predictions.

Insights into quark transverse momentum distributions.

Abstract

Azimuthal asymmetries in unpolarized SIDIS can be used to probe the transverse momentum of the quarks inside the nucleon. Furthermore they give access to the so-far unmeasured Boer-Mulders function. We report on the extraction of these asymmetries from the COMPASS data taken with a 160 GeV/c $\mu ^+$ beam impinging on a deuteron target. This asymmetries have been extracted separately for positive and negative hadrons, and the results have been compared with theoretical predictions.