$P$-even and $P$-odd asymmetries in $^{117}\mathrm{Sn}$ in the vicinity of the $p$ resonance at ${E}_{p}=1.33\phantom{\rule{4pt}{0ex}}\mathrm{eV}$

$P$ -even and $P$ -odd asymmetries in ${}^{117}{Sn}$ in the vicinity of the $p$ resonance at $E_{p} = 1.33 eV$

L. E. Charón-García, L. Barrón-Palos, J. Curole, W. M. Snow, and V. Gudkov (NOPTREX Collaboration)

Phys. Rev. C 109, 014614 – Published 16 January 2024

Abstract

A self-consistent description of angular correlations in neutron-induced reactions is required for quantitative analysis of parity violating (PV) and time-reversal invariance violating (TRIV) effects in neutron-nucleus scattering. The 1.33 eV $p$ -wave compound resonance in ${}^{117}{Sn}$ is one of the few $p$ -wave resonances where enough measurements have been performed to allow a nontrivial test of the internal consistency of the theory. We present the results of a global analysis of the several different asymmetries and angular distribution measurements in ( $n, γ$ ) reactions on the 1.33 eV $p$ -wave resonance in ${}^{117}{Sn}$ conducted over the last few decades. We show that the compound resonance mixing theory can give an internally consistent description of all observations made in this system to date within the experimental measurement errors. We also confirm the conclusions of previous analyses that a subthreshold resonance in ${}^{117}{Sn}$ dominates correlations related to $s − p$ mixing and discuss the implications of these results for future searches for TRIV in this system.