N=16 Spherical Shell Closure in O24
Abstract
The unbound excited states of the neutron drip-line isotope O24 have been investigated via the O24(p,p')O23+n reaction in inverse kinematics at a beam energy of 62MeV/nucleon. The decay energy spectrum of O*24 was reconstructed from the momenta of O23 and the neutron. The spin parity of the first excited state, observed at Ex=4.65±0.14MeV, was determined to be Jπ=2+ from the angular distribution of the cross section. Higher-lying states were also observed. The quadrupole transition parameter β2 of the 21+ state was deduced, for the first time, to be 0.15±0.04. The relatively high excitation energy and small β2 value are indicative of the N=16 shell closure in O24.
- Publication:
-
Physical Review Letters
- Pub Date:
- July 2012
- DOI:
- 10.1103/PhysRevLett.109.022501
- arXiv:
- arXiv:1205.5657
- Bibcode:
- 2012PhRvL.109b2501T
- Keywords:
-
- 21.10.Re;
- 25.40.Ep;
- 27.30.+t;
- Collective levels;
- Inelastic proton scattering;
- 20<
- =A<
- =38;
- Nuclear Experiment
- E-Print:
- to be submitted to Physical Review Letters