The role of A=33 mass chain in Urca Cooling of Accreting Neutron Star Crusts

Transient Low Mass X-ray Binaries (LMXBs) in their quiescent phase are observed to be cooling over timescales of decades. Studying this cooling behavior reveals a great deal of information about the properties of neutron stars. The β-decay/e^- capture cycles lead to an appreciable cooling of the crust but the strength of this Urca cooling depends primarily on the ground-state to ground-state β-decay transition strengths. A = 33 mass chain is supposedly the strongest cooling agent for crusts composed of X-ray burst ashes which relies in part on the strong ground state branch in ³³Mg - ³³Al decay measured with high resolution β-delayed γ-ray spectroscopy. However, ³³Mg has been recently confirmed to have a negative parity ground state making ³³Mg - ³³Al a first-forbidden decay. This leads to a discrepancy with theoretical predictions and the ³³Mg decay experiment results are questioned in the literature, citing Pandemonium effect as a possible reason. I will present the results and ongoing analysis of the re-measurement of the β-decay of ³³Mg experiment performed with the Total Absorption Spectroscopy technique at the National Superconducting Cyclotron Laboratory (NSCL) using NERO/BCS/SuN detector systems.