Breakup channels for C12 triple-α continuum states
Abstract
The triple-α-particle breakup of states in the triple-α continuum of C12 has been investigated by way of coincident detection of all three α particles of the breakup. The states have been fed in the β decay of N12 and B12, and the α particles measured using a setup that covers all of the triple-α phase space. Contributions from the breakup through the Be8(0+) ground state as well as other channels—interpreted as breakup through excited energies in Be8—have been identified. Spins and parities of C12 triple-α continuum states are deduced from the measured phase-space distributions for breakup through Be8 above the ground state by comparison to a fully symmetrized sequential R-matrix description of the breakup. At around 10 MeV in C12, the breakup is found to be dominated by 0+ strength breaking up through the ghost of the Be8(0+) ground state with L=0 angular momentum between the first emitted α particle and the intermediate Be8 nucleus. For C12 energies above the 12.7 MeV 1+ state, however, L=2 breakup of a C12 2+ state through the Be8(2+) excited state dominates. Furthermore, the possibility of a 2+ excited state in the 9-12 MeV region of C12 is investigated.
- Publication:
-
Physical Review C
- Pub Date:
- September 2009
- DOI:
- 10.1103/PhysRevC.80.034316
- Bibcode:
- 2009PhRvC..80c4316D
- Keywords:
-
- Beta decay;
- double beta decay;
- electron and muon capture;
- Stellar helium burning;
- 6< =A< =19;
- 23.40.-s;
- 26.20.Fj;
- 27.20.+n;
- Beta decay;
- double beta decay;
- electron and muon capture;
- Stellar helium burning;
- 6<
- =A<
- =19