Signatures of Moat Regimes in Heavy-Ion Collisions

TL;DR

This paper explores how certain spatially modulated phases, characterized by a moat-shaped energy spectrum, could manifest in heavy-ion collisions, providing potential experimental signatures for detecting such phases.

Contribution

It introduces the concept of moat regimes in QCD phases and models their signatures in heavy-ion collision observables, specifically through a quantum pion liquid example.

Findings

Characteristic momentum dependence of particle correlations predicted

Potential experimental signatures for spatially modulated phases identified

Provides a theoretical framework for future searches in heavy-ion data

Abstract

Heavy-ion collisions at small beam energies have the potential to reveal the rich phase structure of QCD at nonzero temperature and density. Among the possible phases are regimes which feature periodic modulations of the spatial structure, where the energy spectrum is shaped like a moat, with the minimum of the energy over a sphere at nonzero momentum. We argue that if the matter created in heavy-ion collisions traverses such a regime, it can produce a characteristic momentum dependence of particle number and their correlations. As an explicit example, we consider a quantum pion liquid phase to compute these quantities on the freeze-out surface. These results can serve as a first guideline for a systematic search of spatially modulated phases in heavy-ion collisions.