No abstract

No abstract

No abstract

The first investigation of the single-particle structure of the bound states of 17 C , via the d(16 C, p) transfer reaction, has been undertaken. The measured angular distributions confirm the spin-parity assignments of 1/2 + and 5/2 + for the excited states located at 217 and 335 keV, respectively. The spectroscopic factors deduced for these states exhibit a marked single-particle character, in agreement with shell model and particle-core model calculations, and combined with their near degeneracy in energy provide clear evidence for the absence of the N = 14 sub-shell closure. The very small spectroscopic factor found for the 3/2 + ground state is consistent with theoretical predictions and indicates that the ν1d 3/2 strength is carried by unbound states. With a dominant ℓ = 0 valence neutron configuration and a very low separation energy, the 1/2 + excited state is a one-neutron halo candidate.

Motivated by the importance of 25 P for the two-proton decay of 26 S and for searches of the mirror analog of the island of inversion near N = 16, we present the first predictions for the spectroscopy of the exotic isotope 25 P obtained in the shell model, a potential model, and a microscopic-cluster model. All models predict 25 P to be unbound, with an energy in the range 0.78-1.03 MeV, which favors previous mass systematics over more recent revisions. We show that 25 P possesses a rich low-lying spectrum that should be accessible by experimental studies. All of the predicted states below 7 MeV, except one, are narrow. Many of them are built on the excited-core states of 24 Si for which the Coulomb barrier is raised. For decays into the 24 Si(g.s.) + p channel we determined the proton widths based on their link to the asymptotic normalization coefficients (ANCs) of their mirror analogs in 25 Ne. We determine these ANCs from the analysis of the transfer reaction 24 Ne(d,p) 25 Ne. The proton widths for decay into excited-state channels are obtained in model calculations. The only broad state is the intruder 3/2 − , the mirror analog of which has been recently observed in 25 Ne. The 25 P(3/2 − ) energy is lower than that in 25 Ne, suggesting that the island of inversion may persist on the proton-rich side. All excited states of 25 P have at least two decay modes and are expected to populate variously the 2 + 1,2 and 4 + states in 24 Si, which then decay electromagnetically.