Abstract:
The excited states in
63,65,67Mn have been studied via in-beam
\gamma-ray spectroscopy following the knockout reaction of
68Fe by bombarding a liquid hydrogen target. Similar level schemes have been established for the three isotopes, and the level schemes consist of the 11/2
–, 9/2
–, 7/2
– and 5/2
g.s.– states, which are connected by
\Delta I = 1. The level sequences of
65,67Mn show features of strongly coupled rotational band with
K^\pi = 5/2^- expected for the well deformed nuclei. Large-scale shell-model calculations using the modified LNPS (LNPSm) effective interaction reproduce the observed levels remarkably well and suggest the dominance of 4-particle-4-hole (
4p-4h) neutron configurations and 1-particle-1-hole (
1p-1h) proton configurations for all the states. The experimental results show an enhancement of Urca neutrino cooling in the accreted neutron crust associated with
A = 63 nuclei and rule out significant cooling from
A = 65,67.