First Measurement of Neutron Birefringence in Polarized $^{129}$Xe and $^{131}$Xe Nuclei

TL;DR

This paper reports the first measurements of neutron birefringence in polarized xenon isotopes, providing key scattering parameters for future spin-dependent neutron studies and fundamental physics tests.

Contribution

It presents the first experimental determination of neutron incoherent scattering lengths in polarized $^{129}$Xe and $^{131}$Xe nuclei, crucial for interpreting spin-dependent neutron scattering experiments.

Findings

Measured neutron incoherent scattering lengths for $^{129}$Xe and $^{131}$Xe.

Established the neutron birefringence effect in polarized xenon gases.

Provided data essential for future fundamental physics experiments.

Abstract

We present the first measurements of polarized neutron birefringence in transmission through nuclear-polarized $^{129}$Xe and $^{131}$Xe gas and determine the neutron incoherent scattering lengths $b_i(^{129}Xe)=0.186\pm(0.021)_{stat.}\pm(0.004)_{syst.}\space\text{ fm}$ and $b_i(^{131}Xe)=2.09\pm(0.29)_{stat.}\pm(0.12)_{syst.}\space\text{ fm}$ for the first time. These results determine the essential parameter needed for interpretation of spin-dependent neutron-scattering studies on polarized xenon ensembles, with possible future applications ranging from tests of time-reversal violation to mode-entangled neutron scattering experiments on nuclear-polarized systems.