Calculation of the astrophysical S-factor S_12 with the Lorentz integral transform

TL;DR

This paper evaluates the Lorentz integral transform (LIT) method for calculating astrophysical S-factors, demonstrating its reliability and discussing basis choices for improved accuracy in low-energy nuclear reactions.

Contribution

The paper assesses the effectiveness of the LIT approach for S-factor calculations and compares it with traditional methods, highlighting basis selection impacts.

Findings

LIT provides reliable S-factor results when a high density of low-energy states is present.

The hyperspherical basis is less suitable for low-energy S-factor calculations.

An error estimation method for LIT inversion is proposed.

Abstract

The LIT approach is tested for the calculation of astrophysical S-factors. As an example the S-factor of the reaction 2H(p,gamma)3He is considered. It is discussed that a sufficiently high density of LIT states at low energies is necessary for a precise determination of S-factors. In particular it is shown that the hyperspherical basis is not very well suited for such a calculation and that a different basis system is much more advantageous. A comparison of LIT results with calculations, where continuum wave functions are explicitly used, shows that the LIT approach leads to reliable results. It is also shown how an error estimate of the LIT inversion can be obtained.