Breakup channels for {sup 12}C triple-{alpha} continuum states

Journal Article · Tue Sep 15 04:00:00 EDT 2009 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.80.034316· OSTI ID:21293827

Diget, C A ^[1]; Barker, F C ^[2]; Borge, M J. G.; Boutami, R; Tengblad, O ^[3]; Dendooven, P ^[4]; Eronen, T; Jokinen, A; Kankainen, A; Moore, I; Nieminen, A; Penttilae, H; Rinta-Antila, S; Wang, Y; Aeystoe, J ^[5]; Fox, S P; Fulton, B R ^[1]; Fynbo, H O. U.; Hyldegaard, S; Jeppesen, H B ^[6]

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1. Department of Physics, University of York, York, YO10 5DD (United Kingdom)
2. Department of Theoretical Physics, Research School of Physical Sciences and Engineering, Australian National University, Canberra ACT 0200 (Australia)
3. Instituto Estructura de la Materia, CSIC, E-28006 Madrid (Spain)
4. Kernfysisch Versneller Institut, University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands)
5. Department of Physics, University of Jyvaeskylae, FIN-40014 Jyvaeskylae (Finland)
6. Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus (Denmark)

The triple-{alpha}-particle breakup of states in the triple-{alpha} continuum of {sup 12}C 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 {sup 12}N and {sup 12}B, and the {alpha} particles measured using a setup that covers all of the triple-{alpha} phase space. Contributions from the breakup through the {sup 8}Be(0{sup +}) ground state as well as other channels--interpreted as breakup through excited energies in {sup 8}Be--have been identified. Spins and parities of {sup 12}C triple-{alpha} continuum states are deduced from the measured phase-space distributions for breakup through {sup 8}Be above the ground state by comparison to a fully symmetrized sequential R-matrix description of the breakup. At around 10 MeV in {sup 12}C, the breakup is found to be dominated by 0{sup +} strength breaking up through the ghost of the {sup 8}Be(0{sup +}) ground state with L=0 angular momentum between the first emitted {alpha} particle and the intermediate {sup 8}Be nucleus. For {sup 12}C energies above the 12.7 MeV 1{sup +} state, however, L=2 breakup of a {sup 12}C 2{sup +} state through the {sup 8}Be(2{sup +}) excited state dominates. Furthermore, the possibility of a 2{sup +} excited state in the 9-12 MeV region of {sup 12}C is investigated.

• OSTI ID: 21293827
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 3 Vol. 80; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA PARTICLES
BERYLLIUM 8
BETA DECAY
BORON 12
CARBON 12
COMPARATIVE EVALUATIONS
DETECTION
DISTRIBUTION
EXCITED STATES
GROUND STATES
MEV RANGE
NITROGEN 12
PARITY
PHASE SPACE
R MATRIX
SPIN