Exceptional points in the scattering continuum

TL;DR

This paper investigates exceptional points in the scattering continuum of atomic nuclei using a continuum shell model, highlighting their potential experimental observability through phase shift jumps and cross-section variations.

Contribution

It demonstrates the existence of low-energy exceptional points in nuclear scattering and proposes experimental signatures for their detection.

Findings

Low-energy exceptional points occur at realistic coupling values.

Experimental signatures include a 2π phase shift jump.

Cross-section energy dependence is significantly affected near exceptional points.

Abstract

The manifestation of exceptional points in the scattering continuum of atomic nucleus is studied using the real-energy continuum shell model. It is shown that low-energy exceptional points appear for realistic values of coupling to the continuum and, hence, could be accessible experimentally. Experimental signatures are proposed which include the jump by $2\pi$ of the elastic scattering phase shift and a salient energy dependence of cross-sections in the vicinity of the exceptional point.