Parity nonconservation in Fr-like actinide and Cs-like rare-earth-metal ions

TL;DR

This paper calculates parity nonconservation amplitudes in specific ions, identifying promising candidates for new physics searches due to their large amplitudes, stability, and recent experimental trapping.

Contribution

It provides new calculations of PNC amplitudes, energy levels, and transition amplitudes for Fr-like actinide ions and Cs-like rare-earth ions, highlighting potential experimental candidates.

Findings

La 2+, Ac 2+, and Th 3+ ions have large PNC amplitudes and are stable.

232-Th 3+ ions can be experimentally trapped and cooled.

Extended calculations for Ra+ and Ba+ ions, including energy levels and transition amplitudes.

Abstract

Parity nonconservation amplitudes are calculated for the 7s-6d transitions of the francium isoelectronic sequence (Fr, Ra +, Ac 2+, Th 3+, Pa 4+, U 5+ and Np 6+) and for the 6s-5d transitions of the cesium isoelectronic sequence (Cs, Ba +, La 2+, Ce 3+ and Pr 4+). We show in particular that isotopes of La 2+, Ac 2+ and Th 3+ ions have strong potential in the search for new physics beyond the standard model - the PNC amplitudes are large, the calculations are accurate and the nuclei are practically stable. In addition, 232-Th 3+ ions have recently been trapped and cooled [C. J. Campbell et al., Phys. Rev. Lett. 102, 233004 (2009)]. We also extend previous works by calculating the s-s PNC transitions in Ra + and Ba +, and provide new calculations of several energy levels, and electric dipole and quadrupole transition amplitudes for the Fr-like actinide ions.