Two-hadron single target-spin asymmetries: first measurement by HERMES

TL;DR

This paper reports the first measurement of single target-spin asymmetries in semi-inclusive two-pion production using a polarized deuterium target, providing new insights into the transversity distribution function and interference fragmentation functions.

Contribution

It presents the first experimental measurement of these asymmetries and compares them with a theoretical model for interference fragmentation functions.

Findings

Measured single target-spin asymmetries in two-pion production.

Compared experimental results with a model for interference fragmentation functions.

Provided data relevant to the transversity distribution function.

Abstract

Single target-spin asymmetries in semi-inclusive two-pion production were measured for the first time by the HERMES experiment, using a longitudinally polarized deuterium target. These asymmetries relate to the unknown transversity distribution function $h_1(x)$ through, also unknown, interference fragmentation functions. The presented results are compared with a model for the dependence of one of these interference fragmentation functions on the invariant mass of the pion pair.