Transversity Signal in two Hadron Pair Production in COMPASS

TL;DR

This paper reports on measurements of azimuthal asymmetries in two hadron pair production in SIDIS at COMPASS, providing insights into the transversity distribution and fragmentation functions using polarized targets.

Contribution

It presents new preliminary results on two hadron pair asymmetries measured with a proton target, advancing the understanding of transversity in SIDIS.

Findings

Preliminary asymmetry measurements with proton target.

Analysis of two hadron pair production channels.

Insights into transversity distribution functions.

Abstract

Measuring single spin asymmetries in semi-inclusive deep-inelastic scattering (SIDIS) on a transversely polarized target gives a handle to investigate the transversity distribution and transverse momentum dependent distribution functions. In the years 2002, 2003 and 2004 COMPASS took data with a transversely polarized deuteron target and in the year 2007 with a proton target. Three channels for accessing transversity have been analysed. Azimuthal asymmetries in the production of hadron pairs, involving the polarized two hadron interference fragmentation function, azimuthal asymmetries in the production of single hadrons, involving the Collins fragmentation function and polarization measurements of spin-${1/2} \hbar$ particles like $\Lambda$-Hyperons via their self analyzing weak decay. In the following we will focus on new preliminary results from the analysis of two hadron pair asymmetries measured with the proton target.