Limit on Lorentz and CPT violation of the bound Neutron Using a Free Precession 3He/129Xe co-magnetometer

TL;DR

This study uses a 3He/129Xe co-magnetometer to set a new upper limit on Lorentz and CPT violation effects in neutrons by detecting sidereal frequency variations of nuclear spins.

Contribution

It introduces a highly sensitive co-magnetometer setup to improve constraints on Lorentz and CPT violation in neutrons compared to previous experiments.

Findings

Limit on background field bn < 3.7 x 10^{-32} GeV (95% C.L.)

No evidence of sidereal variations detected

Enhanced sensitivity over prior bounds

Abstract

We report on the search for Lorentz violating sidereal variations of the frequency difference of co-located spin-species while the Earth and hence the laboratory reference frame rotates with respect to a relic background field. The co-magnetometer used is based on the detection of freely precessing nuclear spins from polarized 3He and 129Xe gas samples using SQUIDs as low-noise magnetic flux detectors. As result we can determine the limit for the equatorial component of the background field interacting with the spin of the bound neutron to be bn < 3.7 x 10^{-32} GeV (95 C.L.).