Alpha-cluster transfer reactions: A tool for understanding stellar helium burning

Abstract

Nuclear processes not only generate the energy and drive the evolution of stars, but also are responsible for the synthesis of the elements in the Universe. Helium (4He, or α) is the second most abundant element after hydrogen, thus α-particle induced reactions such as (α,γ), (α,n) and (α,p) play a crucial role in nuclear astrophysics, especially for understanding stellar helium burning. Direct measurement of the cross sections for these α-capture reactions at stellar energies is greatly hindered because of the strong Coulomb repulsion. Alpha-cluster transfer reaction is a powerful tool for investigation of astrophysical (α,γ), (α,n) and (α,p) reactions since it can preferentially populate the natural-parity states with an α-cluster structure which dominantly contribute to these astrophysical α-capture reactions during stellar helium burning. In this review we summarize the theoretical scheme, the experimental technique, astrophysical applications and the future perspectives of such approach based on α-cluster transfer reactions.