Speaker
Description
Excited states in 63;65;67Mn were studied via in-beam gamma-ray spectroscopy following the knockout reaction from 68Fe. Similar level schemes, consisting of the 11/2-, 9/2-, 7/2- and 5/2- g.s. level sequence, connected by I → I − 1 transitions, were established, the first time for 65;67Mn. Their level structures show features consistent with strongly-coupled rotational bands with K = 5/2. State-of-the-art shell-model calculations with the modified LNPS effective interaction reproduce the
observed levels remarkably well and suggest 4p−4h neutron and 1p−1h proton configurations for all the states. The data on the low-lying excited states of 53-67Mn provide a textbook example of nuclear structure evolution from weak coupling through decoupling to strong coupling along a single isotopic chain. Our results enhance Urca neutrino cooling from e−capture/beta−decay cycles in the accreted neutron star crust associated with A = 63 nuclei and experimentally rule-out significant cooling from A = 65, 67. This improves constraints that can be made on past surface nuclear burning on accreting neutron stars with observed quiescent cooling light curves.
