Axion-mediated electron-nucleus and electron-electron interactions in the barium monofluoride molecule

The effects induced by the time-reversal (T) and spatial parity (P)-violating electron-nucleus and electron-electron interactions mediated by the axionlike particles (ALPs) in the BaF molecule were estimated. Molecular parameters characterizing these interactions were calculated across a wide range of ALP masses. In the case of the electron-nuclear interaction, the effect of the extended nucleus was studied and shown to be significant for heavy ALPs. Based on the calculated molecular parameters, we obtained a link between the T,P-violating energy shift which can be measured in the ongoing experiment designed to search for the electron electric dipole moment using the BaF molecule (A. Boeschoten et al., arXiV:2303.06402) and the products of coupling constants of the ALP-electron or ALP-electron and ALP-nucleus interactions.