Speaker
Description
Pseudoscalar particles called axions are promising candidates for dark matter constituents [1]. The hypothetical interaction of axions with leptons (e.g., electrons) produces an effective electron-electron interaction. When considering electrons in hexatomic molecules, e.g., RaOCH$_3$, such interaction via axion exchange is capable of violating the parity parity of molecular Hamiltonian. Thus, the theoretical description and experimental study of the electronic structure of such molecules is an excellent way to investigate the $\mathcal{P}$, $\mathcal{T}$-violation effects.
The theoretical description of such systems requires taking into account vibrations and rotations. In order to do so, one should perform calculations with different configurations of the molecule to account for changes in the studied properties. To reduce computational costs, we use the generalized effective core potential (GRECP) to describe the core electrons [2].
The molecular spinors obtained using GRECP have incorrect smoothed behavior in the core region, and parity violation effects are enhanced precisely near the nucleus. To overcome that problem, the one-center restoration (OCR) technique [3] is applied. The latter method has previously been used [4] to calculate one-electron properties; in the current work we generalize it to the case of two-electron properties and apply it to obtain the enhancement parameter for the axion-mediated electron-electron interaction.
The work was supported by the Russian Science Foundation Grant No. 24-72-10060 (https://rscf.ru/project/24-72-10060/).
[1] Preskill, John, Mark B. Wise, and Frank Wilczek. "Cosmology of the invisible axion." {\it{Physics Letters B}} 120.1-3 (1983): 127-132.
[2] Titov, A. V., and N. S. Mosyagin. "Generalized relativistic effective core potential: Theoretical grounds." {\it{International journal of quantum chemistry}} 71.5 (1999): 359-401.
[3] Titov, A. V., et al. "P, T-parity violation effects in polar heavy-atom molecules." {\it{Recent Advances in the Theory of Chemical and Physical Systems}} 253 (2006): 253-283.
[4] Zakharova, Anna. "Symmetric top molecule YbOCH3 in the fundamental P, T-violation searches." {\it{Chemical Physics Letters}} 854 (2024): 141552.
