Jul 17 – 22, 2022
Royal Conservatory of Music, Toronto
America/Toronto timezone

Symmetry-violating properties for precision measurements in diatomic molecules

Jul 18, 2022, 5:00 PM
1h 30m
Hart House (Hart House)

Hart House

Hart House

7 Hart House Cir, Toronto, ON M5S 3H3
Poster presentation Precision measurement and tests of fundamental physics Poster session


High-precision experiments to measure parity (P), and parity and time-reversal (P, T) violation using paramagnetic molecules are a promising route to look for physics beyond the Standard Model of particle physics. Using close-lying opposite-parity molecular states enhances the symmetry-violating experimental signals. This enhancement is purely relativistic and increases with the atomic number [1], making systems containing heavy atoms ideal for symmetry-violation experiments. The enhancement factor can not be measured separately and therefore electronic structure theory is needed to determine its value. This work presents the molecular enhancement for the nuclear spin-dependent P-violating anapole moment in the diatomic molecules containing lanthanum and lutetium heavy atoms. We employ the finite field approach with the relativistic 4-components coupled-cluster method in the DIRAC program [2]. In addition, we present the enhancements factor for the P, T–violating electron electric dipole moment, the P, T–violating electron-nucleus interaction, and the P, T–violating nuclear magnetic quadrupole moment. We pursue a systematic study to estimate the effect of various computational parameters, such as the basis set and electron correlation, on the calculated properties. We have found a consistent dependence of the different symmetry-violating properties on the computational parameters leading to similar uncertainties. The precision of our calculations is approximately 6% and makes the reported enhancement factors suitable for extracting the relevant fundamental properties from future measurements.


[1] Bouchiat M.A., Bouchiat C.C. Journal de Physique (1974), 35, 899-927.

[2] Saue T, Bast R, Gomes AS, et al. The Journal of chemical physics (2020), 152, 204104.

Presenter name Yuly Andrea Chamorro Mena
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Primary authors

Yuly Andrea Chamorro Mena (University of Groningen) Prof. Anastasia Borschevsky (Van Swinderen Institute, University of Groningen)

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