Breakup channels for C-12 triple-alpha continuum states
Journal article, 2009
The triple-alpha-particle breakup of states in the triple-alpha continuum of C-12 has been investigated by way of coincident detection of all three alpha particles of the breakup. The states have been fed in the beta decay of N-12 and B-12, and the alpha particles measured using a setup that covers all of the triple-alpha phase space. Contributions from the breakup through the Be-8(0(+)) ground state as well as other channels-interpreted as breakup through excited energies in Be-8-have been identified. Spins and parities of C-12 triple-alpha continuum states are deduced from the measured phase-space distributions for breakup through Be-8 above the ground state by comparison to a fully symmetrized sequential R-matrix description of the breakup. At around 10 MeV in C-12, the breakup is found to be dominated by 0(+) strength breaking up through the ghost of the Be-8(0(+)) ground state with L = 0 angular momentum between the first emitted alpha particle and the intermediate Be-8 nucleus. For C-12 energies above the 12.7 MeV 1(+) state, however, L = 2 breakup of a C-12 2(+) state through the Be-8(2(+)) excited state dominates. Furthermore, the possibility of a 2(+) excited state in the 9-12 MeV region of C-12 is investigated.
resonances
energy-levels
rates
particle
light-nuclei
be-8
decay
Author
C. A. Diget
F. C. Barker
M. J. G. Borge
R. Boutami
P. Dendooven
T. Eronen
S. P. Fox
B. R. Fulton
H. O. U. Fynbo
J. Huikari
S. Hyldegaard
H. B. Jeppesen
A. Jokinen
Björn Jonson
Chalmers, Applied Physics, Subatomic Physics
A. Kankainen
I. Moore
A. Nieminen
Göran Hugo Nyman
Chalmers, Applied Physics, Subatomic Physics
H. Penttila
V. F. E. Pucknell
K. Riisager
S. Rinta-Antila
Olof Tengblad
Y. Wang
Katarina Wilhelmsen
Chalmers, Applied Physics, Subatomic Physics
J. Aysto
Physical Review C - Nuclear Physics
24699985 (ISSN) 24699993 (eISSN)
Vol. 80 3Subject Categories
Subatomic Physics
Astronomy, Astrophysics and Cosmology
DOI
10.1103/PhysRevC.80.034316