Progress towards a 3D MOT of CaH molecules

Directly laser-cooled and trapped samples of calcium monohydride (CaH) molecules would be useful for ultracold chemistry experiments and potentially serve as a promising route to a dilute, trapped gas of ultracold hydrogen atoms. We previously demonstrated scattering of ~100 photons in CaH, but capturing the molecules in a magneto-optical trap (MOT) requires scattering thousands of photons. A nonradiative decay pathway known as predissociation could limit optical cycling in the process of slowing the molecules to the MOT capture velocity. We present theoretical and experimental estimates of the predissociation probabilities in the states of interest, and demonstrate that a nearly-closed optical cycling scheme is possible. Next, we present our progress on longitudinal white-light slowing and a 3D radio-frequency MOT for CaH. We also show how we could leverage predissociation to engineer an efficient, quantum-state-controlled dissociation pathway to generate ultracold hydrogen.