Study of resonance states in 12N using a radioactive ion beam of 11C

Abstract

Resonance states in 12N were studied by using the resonance elastic scattering of 11C+p with a low-energy radioactive ion beam of 11C at 3.5 MeV/nucleon and a thick (CH2)n target. The 11C beam was separated by a newly installed CNS radioactive ion beam separator (CRIB). The energy spectrum of recoil protons was measured at laboratory scattering angles around θLAB=0° to identify resonance states in 12N. The spin-parity values of Jπ=3− and (2)+ have been determined for the levels at the excitation energies of Ex=3.1 and 3.6 MeV in 12N, respectively, suggesting a small contribution of the 3.1-MeV level to the 11C(p,γ)12N stellar reaction.