30 de maio de 2018 | Estruturas Nucleares e Reações, Publicações
R. Higa, G. Rupak, A. Vaghani
The European Physical Journal A 54, 89 (2018)
30/05/2018
Abstract
In this work we study the radiative capture of 3He on 4He within the halo effective field theory (EFT) framework. At leading order the capture amplitude comprises the initial state s-wave strong and Coulomb interactions summed to all orders. At the same order in the expansion, leading two-body currents contribute as well. We find delicate cancelations between the various contributions, and the two-body current contributions can be replaced by appropriately enhancing the asymptotic normalizations of the 7Be ground and first excited state wave functions. The next-to-leading order corrections come from the s-wave shape parameter and the pure Coulomb d-wave initial state interactions. We fit the EFT parameters to available scattering data and most recent capture data. Our zero-energy astrophysical S-factor estimate, keV b, is consistent within error bars with the average in the literature.