Prospects for Calibrating the New Physics Sensitivity of <sup>229</sup>Pa
ORAL
Abstract
A non-zero permanent electric dipole moment (EDM) would violate parity (P) and time-reversal (T) symmetry, and through the CPT theorem, charge-parity (CP) symmetry is also violated. New sources of CP-violation are necessary to explain the observed baryon asymmetry of the Universe. Detecting a non-zero EDM with current or planned levels of sensitivity would provide evidence for new sources of CP-violation. This nuclear EDM is partially screened by its atomic electrons which are described by the Nuclear Schiff Moment (NSM). The NSM is responsible for inducing the atomic EDM we are seeking to observe. We aim to search for a nearly degenerate ground state parity doublet in 229Pa (Z = 91, τ=1.5 d, I=5/2). If this parity doublet exists, which is thought to have energy splitting consistent with 60 ± 50 eV, then this would significantly enhance the lab-frame NSM and would provide strong motivation for a future search for an NSM of 229Pa, which may be 106 times larger than the NSM for 199Hg. In this presentation, gamma-ray and internal conversion spectroscopy techniques are being explored in order to determine the precise nature of the parity doublet if it exists.
*This material is based upon work supported by the Facility for Rare Isotope Beams, Michigan State University, and the Department of Energy National Nuclear Security Administration through the Nuclear Science and Security Consortium under Award Number(s) DE-NA0003996.
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Presenters
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Adrian M Yearby
- Michigan State University