Imaginary-time method for radiative capture reaction rate

TL;DR

The paper introduces a novel imaginary-time computational method to directly calculate astrophysical radiative capture reaction rates across temperatures, bypassing complex scattering solutions.

Contribution

It presents a new imaginary-time evolution approach for reaction rate calculations, especially useful for complex systems like triple-alpha capture.

Findings

Method yields results identical to traditional calculations for two-body reactions.

Enables direct rate evaluation without scattering problem solutions.

Suitable for complex reactions like triple-alpha capture.

Abstract

We propose a new computational method for astrophysical reaction rate of radiative capture process. In the method, an evolution of a wave function is calculated along the imaginary-time axis which is identified as the inverse temperature. It enables direct evaluation of reaction rate as a function of temperature without solving any scattering problem. The method is tested for two-body radiative capture reaction, ${^{16}{\rm O}}(\alpha,\gamma){^{20}{\rm Ne}}$, showing that it gives identical results to that calculated by the ordinary procedure. The new method will be suited for calculation of triple-alpha radiative capture rate for which an explicit construction of the scattering solution is difficult.