Nuclear-spin-dependent parity-violating anapole moment in diatomic molecules

Precision experiments to measure the nuclear--spin-dependent parity violation (NSD-PV) using molecules are promising. The use of molecules gives the possibility to amplify the observable signals using close-lying opposite parity eigenstates. Specifically, in systems containing heavy nuclei, the NSD-PV effects are dominated by the P-odd anapole moment contribution. The measurement of the anapole moment has a relevant impact on nuclear physics as its value is related to a set of parameters describing low-energy hadronic PV interactions. In this work, we study diatomic molecules containing lanthanum and lutetium heavy atoms, as promising candidates for measuring the anapole moment. We use high--accurate electronic structure methods to calculate the enhancement parameter W_a, which describes the sensitivity of this molecule to the anapole moment, and we estimate the uncertainty in our predictions.