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

The goal of CeNTREX (Cold molecule Nuclear Time-Reversal EXperiment) is to search for fundamental time-reversal symmetry (T) (and hence CP) violation in the hadronic sector. T-violation is included in the Standard Model, but is not sufficient to explain the magnitude of the observed baryon asymmetry in the universe. Many Standard Model extensions propose additional sources of T-violation, and Schiff moments and electronic dipole moments (EDMs) are excellent Standard Model background free probes of this new physics. CeNTREX utilizes shifts in the nuclear magnetic resonance frequencies of the ²⁰⁵Tl nuclear in highly polarized thallium fluoride (TlF) molecules to search for these symmetry violating interactions. With the expected experimental sensitivity we would be able to set competitive bounds on , quark chromo electric dipole moments (EDMs), and the proton EDM. 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.