Alpha clustering in warm and dense nuclear matter from heavy-ion collisions

TL;DR

This study investigates alpha clustering in warm, dense nuclear matter using heavy-ion collision data, revealing unexpectedly high alpha particle fractions with implications for astrophysics.

Contribution

It employs a kinetic model to analyze experimental data, providing new insights into Mott effects and alpha clustering in dense nuclear environments.

Findings

High alpha particle fractions observed in heavy-ion collisions

Alpha clustering persists in warm, dense nuclear matter

Implications for nuclear equation of state and astrophysical phenomena

Abstract

Although light nuclear clusters are known to affect the properties of warm and dilute nuclear matter, their role in warm and dense nuclear matter remains unclear due to the lack of experimental evidence for their modifications by the Mott effect in such an environment. To address this issue, we resort to intermediate-energy heavy-ion collisions, where light clusters are mainly produced in the transiently formed warm and dense matter. A kinetic approach, which includes dynamically the formation and dissociation of light clusters, is employed to deduce the strength of the Mott effects and the $\alpha$-particle fraction in warm and dense nuclear matter from the light-nuclei yields measured by the FOPI Collaboration in central Au$+$Au collisions at energies of $0.25A$ to $0.6A~\rm GeV$. We find an unexpectedly abundant $\alpha$ clustering in this environment, which will have profound implications for modeling the nuclear equation of state and describing supernovae and neutron star mergers.