Berlin 2014 – scientific programme
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A: Fachverband Atomphysik
A 14: Poster: Precision spectroscopy of atoms and ions (with Q)
A 14.11: Poster
Monday, March 17, 2014, 16:30–18:30, Spree-Palais
Testing Lorentz Invariance in the Weak Interaction Using Laser-Polarized 20Na — •Elwin A. Dijck, Auke Sytema, Stefan E. Müller, Steven Hoekstra, Klaus Jungmann, Jacob P. Noordmans, Gerco Onderwater, Coen Pijpker, Rob G. E. Timmermans, Lorenz Willmann, and Hans W. Wilschut — University of Groningen, The Netherlands
Lorentz invariance is one of the fundamental principles underlying our current understanding of nature. In models aiming to unify the Standard Model with (quantum) gravity this symmetry may be broken. Few tests of Lorentz invariance in the weak interaction have been made.
We have performed a novel test of rotational invariance by searching for variations in the decay rate of 20Na nuclei depending on the nuclear spin orientation with respect to a possible Lorentz symmetry breaking background field. Using optical pumping, the nuclei were alternately polarized in opposite vertical directions, while the absolute orientation of the spins changed with the rotation of the Earth.
A polarization-dependent Lorentz symmetry violating effect was searched for, putting a 95% confidence limit on the amplitude of sidereal variations in the decay rate asymmetry at < 3 × 10−3. This result was analyzed in the framework of a recently developed theory that assumes a Lorentz symmetry breaking background field of tensor nature.