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

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 ${\sigma }_P^{\text{syst}}/P\le 1\%$. 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 ${\delta }^{\text{syst}}P/P\lesssim 0.5\%$. 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.

Comments: 10 pages, 8 figures, Presented at the VIII international conference on High Energy Physics in the LHC Era, Jan 9-13, 2023, Valparaiso, Chile