Lambda transverse polarization in NA61\SHINE at the CERN SPS: feasibility studies

TL;DR

This study assesses the feasibility of measuring Lambda hyperon transverse polarization in NA61 ext{SHINE} at CERN SPS, considering magnetic field effects and detector acceptance, and finds that polarization signals are detectable despite biases.

Contribution

It provides a detailed feasibility analysis for polarization measurements in NA61 ext{SHINE}, highlighting the minimal impact of magnetic precession and the potential to observe known polarization signals.

Findings

Magnetic field impact on polarization is negligible compared to detector biases.

Detection of polarization signals similar to previous experiments is feasible.

Analysis supports future polarization measurements in NA61 ext{SHINE}.

Abstract

The spin polarization of $\Lambda$ hyperons produced in inclusive reactions with unpolarized protons on unpolarized targets has been studied for almost 40 years. The NA61\SHINE experiment at the CERN SPS has a great potential to study transverse polarization in p-p and p-A collisions. In this work, we discuss the impact of magnetic field and limited detector acceptance on the possible polarization measurement by this experiment. Our analysis shows that the magnetic field impact on the $\Lambda$ polarization due to precession is one order of magnitude smaller than the detector acceptance-based polarization bias, and the identification of an experimental signal similar to that observed before by other experiments is possible.