Longitudinal Spin Transfer to the $\Lambda$ Hyperon in Semi-Inclusive Deep-Inelastic Scattering

TL;DR

This paper reports on the measurement of polarization transfer from polarized positrons to \\Lambda hyperons in semi-inclusive deep-inelastic scattering, providing insights into spin dynamics in high-energy particle interactions.

Contribution

It presents the first measurement of longitudinal spin transfer to \\Lambda hyperons in semi-inclusive deep-inelastic scattering at DESY, including dependence on energy fraction and momentum.

Findings

Longitudinal spin transfer coefficient \\dll = 0.11 \\pm 0.10 (stat) \\pm 0.03 (syst).

Dependence of \\dll on fractional energy z and momentum x_F is analyzed.

Results contribute to understanding of spin transfer mechanisms in high-energy scattering.

Abstract

The transfer of polarization from a high-energy positron to a \lam hyperon produced in semi-inclusive deep-inelastic scattering has been measured. The data have been obtained by the HERMES experiment at DESY using the 27.6 GeV longitudinally polarized positron beam of the HERA collider and unpolarized gas targets internal to the positron (electron) storage ring. The longitudinal spin transfer coefficient is found to be $\dll = 0.11 \pm 0.10 \mathrm{(stat)} \pm 0.03 \mathrm{(syst)}$ at an average fractional energy carried by the \lam hyperon $<z >= 0.45$. The dependence of \dll on both the fractional energy $z$ and the fractional longitudinal momentum $x_F$ is presented.