alpha-cluster asymptotic normalization coefficients for nuclear astrophysics

作者：Avila M L^*; Rogachev G V; Koshchiy E; Baby L T; Belarge J; Kemper K W; Kuchera A N; Santiago Gonzalez D

来源：Physical Review C, 2014, 90(4): 042801.

DOI：10.1103/PhysRevC.90.042801

Background: Many important alpha-particle induced reactions for nuclear astrophysics may only be measured using indirect techniques due to the small cross sections at the energy of interest. One such indirect technique is to determine the asymptotic normalization coefficients (ANCs) for near-threshold resonances extracted from sub-Coulomb alpha-transfer reactions. This approach provides a very valuable tool for studies of astrophysically important reaction rates since the results are practically model independent. However, the validity of the method has not been directly verified.
Purpose: The aim of this Rapid Communication is to verify the technique using the O-16(Li-6, d)Ne-20 reaction as a benchmark. The Ne-20 nucleus has a well-known 1(-) state at an excitation energy of 5.79 MeV with a width of 28 eV. Reproducing the known value with this technique is an ideal opportunity to verify the method.
Method: The 1(-) state at 5.79 MeV is studied using the a-transfer reaction O-16(Li-6, d)Ne-20 at sub-Coulomb energies.
Results: The partial alpha width for the 1-state at excitation energy of 5.79 MeV is extracted and compared with the known value, allowing the accuracy of the method to be evaluated.
Conclusions: This study demonstrates that extracting the ANCs using sub-Coulomb alpha-transfer reactions is a powerful tool that can be used to determine the partial a width of near-threshold states that may dominate astrophysically important nuclear reaction rates.

• 出版日期2014-10-15