# Improved Analysis of the Breakup Corrections to the High Energy $^3$He Beam Polarization measurements with HJET

## TL;DR

This paper refines the analysis of breakup corrections in high-energy $^3$He beam polarization measurements using HJET, confirming that these corrections are negligible for the EIC, thus enabling more precise polarization determinations.

## Contribution

It provides a more accurate assessment of breakup corrections in $^3$He polarization measurements with HJET, ensuring the systematic uncertainties meet EIC requirements.

## Key findings

- Breakup corrections are negligible for EIC helion beam polarization.
- The analysis confirms the validity of using HJET for high-precision $^3$He polarization.
- The study improves the understanding of spin-flip and breakup effects in polarization measurements.

## Abstract

The requirements for hadron polarimetry at the future Electron Ion Collider (EIC) include measurements of the absolute helion ($^3$He, $h$) beam polarization with systematic uncertainties better than $\sigma^\text{syst}_P/P\le1\%$. Recently, it was suggested to utilize the Polarized Atomic Hydrogen Gas Jet Target (HJET) for precision measurement of the polarization of the $\sim$100 GeV/n helion beam. At the Relativistic Heavy Ion Collider, HJET serves to determine absolute proton beam polarization with low systematic uncertainties of about $\delta^\text{syst}P/P\lesssim0.5\%$. To adapt the HJET method for the EIC helion beam, the experimentally determined ratio of the beam and target (jet) spin correlated asymmetries should be adjusted by the ratio of $p^\uparrow{h}$ and $h^\uparrow{p}$ analyzing powers $A_\text{N}^{ph}(t)/A_\text{N}^{hp}(t)$ which, in the leading order approximation, is predefined by magnetic moments of the proton and helion, $(\mu_p-1)/(\mu_h/2-1/3)$. However, to achieve the required accuracy in the measured polarization, the corrections due to hadronic spin-flip amplitudes and due to possible beam $^3$He breakup should be considered. Here a more accurate analysis of the possible breakup corrections to the measured $^3$He beam polarization is provided. The results confirm that the breakup corrections are negligible for the EIC helion beam absolute polarization measurement by HJET.