Progress towards a nuclear Schiff moment measurement using 205TlF molecules in CeNTREX*

The aim of CeNTREX (Cold molecule Nuclear Time-Reversal EXperiment) is to search for the time-reversal and parity-violating Schiff moment of the 205Tl nucleus. With the expected experimental sensitivity we would be able to set competitive bounds on θ_QCD, quark chromo electric dipole moments (EDMs), and the proton EDM. The energy shift resulting from the 205 Tl Schiff moment is amplified in the polar molecule thallium fluoride (TlF), relative to the case in atoms. We employ two methods to maximize population in the science state used in the measurement: rotational cooling to pump several rotational states into a single hyperfine level of the J=0 rotational level of the ¹Σ⁺ electronic ground state and electrostatic focusing with a quadrupole lens. Rotational cooling pumps population into the J=0 state, but the electrostatic lens requires a weak field seeking state with J=2 and the science state has J=1. This requires multiple quantum state transfer stages, which we perform using adiabatic passage with microwaves. Finally, the Schiff moment measurement requires nulling of the magnetic fields in the interaction region to within 10 uG, which is achieved with a combination of passive magnetic shielding and shim coils. This talk will discuss progress towards the nuclear Schiff moment measurement.