title: Constraining the 6.05 MeV 0+ and 6.13 MeV 3- cascade transitions in the 12C(α,γ)16O reaction using the asymptotic normalization coefficients.
abstract: The 12C(α,γ)^16O reaction plays a fundamental role in astrophysics and needs to be known with accuracy better than 10%. Cascade γ transitions through the excited states of 16 O are contributing to the uncertainty. We constrained the contribution of the 0+ (6.05 MeV) and 3- (6.13 MeV) cascade transitions by measuring the asymptotic normalization coefficients for these states using the α-transfer reaction 6 Li(12C,d)^16O at sub-Coulomb energy. The contribution of the 0+ and 3- cascade transitions at 300 keV is found to be 1.96 ± 0.3 and 0.12 ± 0.04  keV b for destructive interference of the direct and resonance capture and 4.36 ± 0.45 and 1.44 ± 0.12  keV b for constructive interference, respectively. The combined contribution of the 0+ and 3- cascade transitions to the 12C(α,γ)16O reaction cross section at 300 keV does not exceed 4%. Significant uncertainties have been dramatically reduced.
authors.affiliation: Department of Physics, Florida State University, Tallahassee, Florida 32306, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Avila
authors.affiliation: Department of Physics & Astronomy and Cyclotron Institute, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: G V
authors.initials: GV
authors.lastname: Rogachev
authors.affiliation: Department of Physics & Astronomy and Cyclotron Institute, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: E
authors.initials: E
authors.lastname: Koshchiy
authors.affiliation: Department of Physics, Florida State University, Tallahassee, Florida 32306, USA.
authors.forename: L T
authors.initials: LT
authors.lastname: Baby
authors.affiliation: Department of Physics, Florida State University, Tallahassee, Florida 32306, USA.
authors.forename: J
authors.initials: J
authors.lastname: Belarge
authors.affiliation: Department of Physics, Florida State University, Tallahassee, Florida 32306, USA.
authors.forename: K W
authors.initials: KW
authors.lastname: Kemper
authors.affiliation: Department of Physics, Florida State University, Tallahassee, Florida 32306, USA.
authors.forename: A N
authors.initials: AN
authors.lastname: Kuchera
authors.affiliation: Department of Physics & Astronomy and Cyclotron Institute, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Mukhamedzhanov
authors.affiliation: Department of Physics, Florida State University, Tallahassee, Florida 32306, USA.
authors.forename: D
authors.initials: D
authors.lastname: Santiago-Gonzalez
authors.affiliation: Department of Physics & Astronomy and Cyclotron Institute, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: E
authors.initials: E
authors.lastname: Uberseder