Probing Fundamental Symmetries of Deformed Nuclei in Symmetric Top Molecules

Abstract

Precision measurements of Schiff moments in heavy, deformed nuclei are sensitive probes of beyond standard model T, P violation in the hadronic sector. While the most stringent limits on Schiff moments to date are set with diamagnetic atoms, polar polyatomic molecules can offer higher sensitivities with unique experimental advantages. In particular, symmetric top molecular ions possess K doublets of opposite parity with especially small splittings, leading to full polarization at low fields, internal comagnetometer states useful for rejection of systematic effects, and the ability to perform sensitive searches for T, P violation using a small number of trapped ions containing heavy exotic nuclei. We consider the symmetric top cation 225RaOCH þ 3 as a prototypical and candidate platform for performing sensitive nuclear Schiff measurements and characterize in detail its internal structure using relativistic ab initio methods. The combination of enhancements from a deformed nucleus, large polarizability, and unique molecular structure make this molecule a promising platform to search for fundamental symmetry violation even with a single trapped ion.

Isotope Shifts of Radium Monofluoride Molecules

“…Such information is especially interesting for exotic actinide species. These nuclei and their molecular compounds are of marked interest for nuclear structure and fundamental symmetry studies [2,12,[51][52][53][54][55][56][57][58][59][60][61], but until now the experimental knowledge of their molecular and nuclear properties is lacking. Our findings offer important information to understand nuclear structure and symmetry-violating effects in molecules containing the heaviest elements of the periodic table.…”

Sliding Naturalness: Cosmological Selection of the Weak Scale

“…The red shaded region (dashed line) shows bounds[79] (future prospects[80][81][82]) from hadronic EDM searches. New ideas involving molecular compounds could further improve future sensitivities[83][84][85][86][87]. We also plot in black constraints on fuzzy DM from Lyman-α forest[88][89][90][91][92][93], measurements of the subhalo mass function[94] and the Eridanus II dwarf galaxy[95] (similar to the constraints from other dwarf galaxies[96,97]).…”

Sizing up Exotic Nuclei with Radioactive Molecules

“…One promising approach to finding these violations lies in studying certain pear-shaped radioactive nuclei within polar molecules (see Viewpoint: Designer Molecules for Fundamental-Symmetry Tests). Research has shown that the energy spectra of such molecules are exceptionally sensitive probes of symmetry violations [3,4]. To harness this discovery potential, researchers need to develop a better understanding of the energy spectra of these radioactive molecules.…”