Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10723547 | Physics Letters B | 2011 | 5 Pages |
Abstract
The radiative capture reaction C12(α,γ)O16 has been investigated in the energy range E=3.3 to 4.5 MeV. This experiment focused in particular on the cascade transition to the 0+ state at Ex=6.05 MeV in 16O and was performed by detecting the capture γ-rays with a NaI detector array at the windowless 4He gas target of the recoil mass separator ERNA in coincidence with the 16O ejectiles. The 6.05 MeV transition has been considered recently as a component accounting for up to 15% of the C12(α,γ)O16 total cross section at astrophysical energies. The arrangement of the detector array yielded additional information on the γ-ray multipolarity, i.e. the ratio ÏE2/ÏE1, and it was found that the 6.05 MeV transition is entirely E2 in the studied energy range. The results for this transition are analyzed in an R-matrix formalism and extrapolated to the relevant Gamow energy of stellar helium burning, E0â300 keV. In contrast to a previous analysis, the present extrapolation suggests a negligible contribution from this amplitude, S6.05(300)<1 keVb. Additional data for cascade transitions to excited states at Ex=6.13, 6.92, and 7.12 MeV, respectively, as well as to the ground state were obtained and the corresponding S factors in the studied energy range are given.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Nuclear and High Energy Physics
Authors
D. Schürmann, A. Di Leva, L. Gialanella, R. Kunz, F. Strieder, N. De Cesare, M. De Cesare, A. DʼOnofrio, K. Fortak, G. Imbriani, D. Rogalla, M. Romano, F. Terrasi,