The {sup 12}C({alpha}, {gamma}){sup 16}O E2 cross section at stellar energies

Journal Article · Thu Aug 12 00:00:00 EDT 2010 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3485147· OSTI ID:21435989

Descouvemont, P ^[1]; Dufour, M ^[2]

---

1. Physique Nucleaire Theorique et Physique Mathematique, C.P. 229, Universite Libre de Bruxelles (ULB), B 1050 Brussels (Belgium)
2. IPHC Bat27, IN2P3-CNRS/Universite Louis Pasteur BP28, F-67037 Strasbourg Cedex 2-France (France)

The E2 component of the {sup 12}C({alpha}, {gamma}){sup 16}O cross section is investigated by a microscopic cluster model, and by R-matrix fits. The first approach provides S{sub E2}(300 keV){approx_equal}50 keV-b for ground-state transitions. In the R-matrix theory, we show that the background term plays a crucial role, and cannot be determined without ambiguity. Only an upper limit on the extrapolated S factor can be obtained [S{sub E2}(300 keV)<190 keV-b]. To constrain the R-matrix analysis, we use the GCM Asymptotic Normalization Constant (ANC) of the 2{sub 1}{sup +} level. This procedure strongly reduces the uncertainties on the R-matrix fit, and we end up with a recommended value of S{sub E2}(300 keV) =42{+-}2 keV-b. As ANC values derived from indirect methods are not consistent with the {sup 12}C({alpha}, {gamma}){sup 16}O cascade transitions to the 2{sub 1}{sup +} state, we suggest a remeasurement of this cross section.

• OSTI ID: 21435989
• Journal Information: AIP Conference Proceedings, Vol. 1269, Issue 1; Conference: OMEG-2010: 10. international symposium on origin of matter and evolution of galaxies, Osaka (Japan), 8-10 Mar 2010; Other Information: DOI: 10.1063/1.3485147; (c) 2010 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA REACTIONS
ASYMPTOTIC SOLUTIONS
CARBON 12 TARGET
CLUSTER MODEL
CROSS SECTIONS
E2-TRANSITIONS
KEV RANGE
NUCLEON-NUCLEON INTERACTIONS
OXYGEN 16
PHOTONS
R MATRIX
RESONANCE
SPIN
ANGULAR MOMENTUM
BARYON-BARYON INTERACTIONS
BOSONS
CHARGED-PARTICLE REACTIONS
ELEMENTARY PARTICLES
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EVEN-EVEN NUCLEI
HADRON-HADRON INTERACTIONS
INTERACTIONS
ISOTOPES
LIGHT NUCLEI
MASSLESS PARTICLES
MATHEMATICAL MODELS
MATHEMATICAL SOLUTIONS
MATRICES
MULTIPOLE TRANSITIONS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
OXYGEN ISOTOPES
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
STABLE ISOTOPES
TARGETS