Invariant-mass spectroscopy of O14 excited states
/ Authors
R. Charity, K. W. Brown, J. Okołowicz, M. Płoszajczak, J. Elson, W. Reviol, L. Sobotka, W. Buhro, Z. Chajęcki, W. G. Lynch
and 8 more authors
J. Manfredi, R. Shane, R. Showalter, M. Tsang, D. Weisshaar, J. Winkelbauer, S. Bedoor, A. Wuosmaa
/ Abstract
Excited states in $^{14}$O have been investigated both experimentally and theoretically. Experimentally, these states were produced via neutron-knockout reactions with a fast $^{15}$O beam and the invariant-mass technique was employed to isolate the 1$p$ and 2$p$ decay channels and determine their branching ratios. The spectrum of excited states was also calculated with the Shell Model Embedded in the Continuum that treats bound and scattering states in a unified model. By comparing energies, widths and decay branching patterns, spin and parity assignments for all experimentally observed levels below 8 MeV are made. This includes the location of the second 2$^{+}$ state that we find is in near degeneracy with the third 0$^{+}$ state. An interesting case of sequential 2$p$ decay through a pair of degenerate $^{13}$N excited states with opposite parities was found where the interference between the two sequential decay pathways produces an unusual relative-angle distribution between the emitted protons.
Journal: Physical Review C