MTV/MTV-G Experiment at TRIUMF Search of T-Violation and Gravity Signal at Nuclear Scale

Abstract

The MTV-G (MTV-Gravity) experiment is aiming to detect a strong gravitational field at around nuclear scale, utilizing an electron polarimeter of the MTV (Mott Polarimetry for T-Violation) experiment [1], which is searching a large T-Violating electron transverse polarization emitted in polarized Li-8 beta decay. The MTV experiment is running at TRIUMF-ISAC since 2009, yielding the highest precision test of T-Violation. The extreme sensitivity of the MTV polarimeter gives us an opportunity to perform a new type of gravity experiment. A modification of gravitational inverse square law at a microscopic scale is predicted by a large extra-dimension model in order to explain the hierarchy problem. The strong gravitational field can be detected as a large spin precession of electrons scattered from nuclei, caused by the “Geodetic precession” as a result of a warped space-time around the nuclear mass. In this experiment, longitudinal polarization of electrons emitted from a 90 Sr source is transferred into a transverse polarization via electromagnetic Thomas precession and possibly via the Geodetic precession.