Many Body Approach for Quartet Condensation in Strong Coupling

TL;DR

This paper develops a self-consistent theoretical framework for quartet condensation in strongly coupled fermionic systems, exemplified by alpha particle condensation in nuclear matter, highlighting the breakdown of quasiparticle approximation.

Contribution

It introduces nonlinear equations for the quartet order parameter and derives a tractable approximation, advancing understanding of higher fermionic cluster condensation.

Findings

Formulated self-consistent equations for quartet condensation.

Applied the theory to alpha particles in nuclear matter.

Identified the breakdown of the quasiparticle picture in strong coupling.

Abstract

The theory for condensation of higher fermionic clusters is developed. Fully selfconsistent nonlinear equations for the quartet order parameter in strongly coupled fermionic systems are established and solved. The breakdown of the quasiparticle picture is pointed out. Derivation of numerically tractable approximation is described. The momentum projected factorisation ansatz of Ref. \cite{slr09} for the order parameter is employed again. As a definite example the condensation of $\alpha$ particles in nuclear matter is worked out.