Dynamical Screening of $\alpha$-$\alpha$ Resonant Scattering and Thermal Nuclear Scattering Rate in a Plasma

TL;DR

This paper investigates how dynamical screening in a QED plasma affects alpha-alpha resonant scattering and nuclear reaction rates, revealing significant suppression at certain temperatures with implications for astrophysics.

Contribution

It introduces a detailed analysis of dynamical screening effects on alpha-alpha scattering using effective and thermal field theories, highlighting the impact on resonance properties and reaction rates.

Findings

Dynamical screening adds an imaginary part to the potential, increasing resonance width.

Resonance energy and width increase with plasma temperature.

Thermal nuclear scattering rate can be suppressed by a factor of about 900 at 10 keV.

Abstract

We use effective field theory and thermal field theory to study the dynamical screening effect in the QED plasma on the $\alpha$-$\alpha$ scattering at the $^8$Be resonance. Dynamical screening leads to an imaginary part of the potential which results in a thermal width for the resonance and dominates over the previously considered static screening effect. As a result, both the resonance energy and width increase with the plasma temperature. Furthermore, dynamical screening can have a huge impact on the $\alpha$-$\alpha$ thermal nuclear scattering rate. For example, when the temperature is around $10$ keV, the rate is suppressed by a factor of about $900$. We expect similar thermal suppressions of nuclear reaction rates to occur in those reactions dominated by an above threshold resonance with a thermal energy. Dynamical screening effects on nuclear reactions can be relevant to cosmology and astrophysics.