Towards a measurement of the nuclear anapole moment of ¹³⁷Ba in BaF molecules

We discuss our progress towards measuring the parity-violating nuclear anapole moment of ¹³⁷Ba in barium monofluoride (BaF) molecules. We present an outline of our quantum-enabled measurement scheme, which was used recently to measure the NSD-PV (nuclear spin dependent parity violating) effect due to the ¹⁹F nucleus in ¹³⁸Ba¹⁹F. A sensitivity sufficient to measure the predicted effect in ¹³⁷BaF, at the 10% level, was achieved. Several major improvements have since been incorporated into the system, such as a cryogenic buffer gas beam source and an improved laser frequency locking scheme. Both the A ²Π_1/2 and D ²Σ⁺ states of BaF are used for the quantum state preparation and detection needed to measure the anapole moment in ¹³⁷Ba. We will present recent measurements of the hyperfine splittings of the A ²Π_1/2 state, and progress towards further spectroscopy of both this state and the D ²Σ⁺ state. We will also discuss new schemes to enhance the usable signal size in the low-abundance isotopomer ¹³⁷BaF.