Low-lying single-particle structure of 17C and the N = 14 sub-shell closure

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.

Transfer reactions of exotic nuclei including core deformations: Be11 and C17

“…This value is consistent with the value β = 0.7 extracted from the PAMD model following the prescription of Ref. [8] and considering the inflection point of the central potential as R. Our Nilsson model also uses h/2J = 0.56 MeV for the 10 Be core, which is compatible with the excitation energy of its first 2 + state (3.368 MeV [32]). With the rest of the parameters already set, the parity-dependent strength is adjusted slightly to reproduce the experimental energies of the bound states (52.43 MeV for positive-parity states and 49.62 MeV for negative ones).…”

“…To assess the quality and reliability of the developed models, the calculated wave functions are applied to transfer reactions involving these nuclei. Two transfer reactions have been studied by implementing the results of the structure calculations, 16 C(d, p) 17 C and 11 Be(p, d ) 10 Be. The adiabatic distorted-wave approximation (ADWA) [11] has been used for this purpose.…”

“…In Sec. V we study the reactions 16 C(d, p) 17 C and 11 Be(p, d ) 10 Be. Finally, we discuss the main results in Sec.…”

Investigation of negative-parity states in 16C via deuteron inelastic scattering *

“…A 16 C secondary beam was produced from a 59.6-MeV/nucleon 18 O primary beam impinging on a 4.5-mmthick 9 Be target. The secondary beam was purified and transmitted by the Radioactive Ion Beam Line in Lanzhou (RIBLL), Institute of Modern Physics (IMP), China.…”

“…This variation can lead to the disappearance of conventional magic number N = 8 and the appearance of new magic number N = 14 or N = 16. Our experimental results obtained from the single-nucleon transfer reactions of 11 Be on proton and deuteron targets imply the breakdown of the magic number N = 8 and the strong intrusion of the -shell in 11 Be and 12 Be [3][4][5][6][7][8][9]. As another well-known example, a systematic comparison of the energies of the 2 states in neutron-rich oxygen and carbon isotopes and the study of the evolution of single-particle…”