Radiative capture reaction for Ne 17 formation within a full three-body model

Abstract

Background: The breakout from the hot Carbon-Nitrogen-Oxigen (CNO) cycles can trigger the rp-process in type I x-ray bursts. In this environment, a competition between 15O(α,γ )19Ne and the two-proton capture reaction 15O(2p,γ )17Ne is expected. Purpose: Determine the three-body radiative capture reaction rate for 17Ne formation including sequential and direct, resonant and nonresonant contributions on an equal footing. Method: Two different discretization methods have been applied to generate 17Ne states in a full three-body model: the analytical transformed harmonic oscillatormethod and the hyperspherical adiabatic expansionmethod. The binary p-15O interaction has been adjusted to reproduce the known spectrum of the unbound 16F nucleus. The dominant E1 contributions to the 15O(2p,γ )17Ne reaction rate have been calculated from the inverse photodissociation process. Results: Three-body calculations provide a reliable description of 17Ne states. The agreement with the available experimental data on 17Ne is discussed. It is shown that the 15O(2p,γ )17Ne reaction rates computed within the two methods agree in a broad range of temperatures. The present calculations are compared with a previous theoretical estimation of the reaction rate. Conclusions: It is found that the full three-body model provides a reaction rate several orders of magnitude larger than the only previous estimation. The implications for the rp-process in type I x-ray bursts should be investigated.