New Limit on Lorentz-Invariance- and CPT-Violating Neutron Spin Interactions Using a Free-Spin-Precession He3-Xe129 Comagnetometer
Abstract
We report on the search for a CPT- and Lorentz-invariance-violating coupling of the He3 and Xe129 nuclear spins (each largely determined by a valence neutron) to posited background tensor fields that permeate the Universe. Our experimental approach is to measure the free precession of nuclear spin polarized He3 and Xe129 atoms in a homogeneous magnetic guiding field of about 400 nT using LTC SQUIDs as low-noise magnetic flux detectors. As the laboratory reference frame rotates with respect to distant stars, we look for a sidereal modulation of the Larmor frequencies of the colocated spin samples. As a result we obtain an upper limit on the equatorial component of the background field interacting with the spin of the bound neutron b ∼⊥n<8.4×10-34 GeV (68% C.L.). Our result improves our previous limit (data measured in 2009) by a factor of 30 and the world's best limit by a factor of 4.
- Publication:
-
Physical Review Letters
- Pub Date:
- March 2014
- DOI:
- 10.1103/PhysRevLett.112.110801
- arXiv:
- arXiv:1312.3225
- Bibcode:
- 2014PhRvL.112k0801A
- Keywords:
-
- 32.10.Dk;
- 07.55.Ge;
- 11.30.Cp;
- 11.30.Er;
- Electric and magnetic moments polarizability;
- Magnetometers for magnetic field measurements;
- Lorentz and Poincare invariance;
- Charge conjugation parity time reversal and other discrete symmetries;
- General Relativity and Quantum Cosmology;
- Physics - Atomic Physics
- E-Print:
- 5 pages, 2 figures. arXiv admin note: text overlap with arXiv:1011.2143