Abstract
Two high-lying states in and , unbound with respect to one-proton () and two-proton () emissions, have been observed in the fragmentation of at intermediate energies. They undergo mainly sequential emissions of protons via intermediate states in and and have decay energies of 7.8(2) and 7.6(2) MeV, respectively. The widths of the newly observed states in and are much smaller than the Wigner limits for single-particle configurations, of 0.4(4) and MeV, respectively. In addition, narrow widths of 0.2(2) MeV are derived for two other high-lying states in with of 4.9 and 6.4 MeV, which match features of the recently predicted narrow odd-parity states with two valence protons in the shell. All energies and widths have been obtained by analyzing angular correlations of the decay products, and , whose trajectories have been measured by a tracking technique with silicon microstrip detectors.
- Received 15 April 2009
DOI:https://doi.org/10.1103/PhysRevC.79.061301
©2009 American Physical Society