First ab initio estimate of the fluorine-19 nuclear Schiff moment

What the study found: The study reports the first-ever calculation of a nuclear Schiff moment, a quantity sensitive to violations of time-reversal and parity-inversion symmetries, in an ab initio nuclear framework for fluorine-19. The authors also connect this calculation to sensitivity estimates for the hafnium monofluoride cation, HfF+, and to the first experimental bound on the nuclear Schiff moment of fluorine-19.
Why the authors say this matters: The authors conclude that their work lays the foundation for using nuclear ab initio methods to constrain pion-nucleon-nucleon (πNN) interactions. They also state that, although the resulting bounds on πNN coupling constants are not yet the most stringent, the approach is relevant for probing physics beyond the standard model.
What the researchers tested: The researchers used the no-core shell model, an ab initio nuclear structure method that treats all nucleons explicitly, to study fluorine-19. They then carried out quantum-chemistry calculations to determine how sensitive HfF+ is to the nuclear Schiff moment of fluorine-19, and combined this with recent high-precision measurements of the molecular electric dipole moment of HfF+.
What worked and what didn't: The combined calculations and measurements enabled the first experimental bound on the nuclear Schiff moment of fluorine-19. The abstract says the resulting bounds on πNN coupling constants are not yet the most stringent.
What to keep in mind: The abstract does not give numerical values for the Schiff moment or the bounds. It also does not describe detailed limitations beyond noting that the πNN bounds are not yet the strongest.

Key points

• The paper reports the first ab initio calculation of a nuclear Schiff moment for fluorine-19.
• The work combines no-core shell model calculations with quantum-chemistry calculations for HfF+.
• Recent high-precision measurements of the HfF+ molecular electric dipole moment were used to obtain the first experimental bound on the fluorine-19 Schiff moment.
• The authors say the study lays the foundation for constraining πNN interactions with nuclear ab initio methods.
• The abstract notes that the resulting πNN coupling bounds are not yet the most stringent.