A new avenue in the search for CP violation: Mössbauer spectroscopy of 227Ac

Citation

Scheck M, Chapman R, Dobaczewski J, Ederer C, Ivanov P, Lorusso G, O’Donnell D & Schroeder C (2023) A new avenue in the search for CP violation: Mössbauer spectroscopy of 227Ac. European Physical Journal A: Hadrons and Nuclei, 59 (5), Art. No.: 116. https://doi.org/10.1140/epja/s10050-023-01000-z

Abstract
This work proposes a new avenue in the search for CP-violating odd-electric and even-magnetic nuclear moments. A promising candidate to find such moments in the ground state is the quadrupole-deformed and octupole-correlated nucleus 227-actinium. In this nucleus, the 27.4-keV E1 transition that connects the 3/2+ parity-doublet partner and the 3/2− ground state is perfectly suited to apply the sensitive technique of recoil-free selfabsorption, commonly known as Mössbauer spectroscopy. In this experimental approach, the lifetime of the 3/2+ upper parity-doublet partner allows an estimate of the lower limit of ΔE=2⋅Γγ= 23.7(1) × 10−9 eV for the achievable energy resolution to be made. This resolution must be exceeded by the interaction of a CP-violating moment and the corresponding multipole moment of the field distribution in the lattice. This work presents the first ideas for patterns caused by CP-violating moments on the expected quadrupole splitting and nuclear Zeeman effect.

Keywords
Quadrupole-octupole coupling: CP-violating moments: Mössbauer spectroscopy: Quadrupole spliting: Nuclear Zeeman effect:

Journal
European Physical Journal A: Hadrons and Nuclei: Volume 59, Issue 5

• S10050-023-01000-z