Nucleon Short-Range Correlations and High-Momentum Dynamics: Implications on the Equation of State of Dense Matter

TL;DR

This review explores how nucleon short-range correlations and high-momentum tails influence the nuclear equation of state, with implications for heavy-ion reactions and neutron-star properties, highlighting recent empirical and theoretical insights.

Contribution

It provides a comprehensive overview of SRC features and their impact on the EOS of dense matter, integrating empirical data, theoretical models, and astrophysical implications.

Findings

SRCs significantly modify the kinetic and potential parts of the nuclear EOS.

High-momentum tails lead to a softening of the kinetic symmetry energy.

Impacts on heavy-ion collision observables and neutron-star characteristics are discussed.

Abstract

Nucleon short-range correlations (SRCs) and their high-momentum tails (HMTs) encode key short-range dynamics in nuclei and dense matter. This review provides a concise overview of SRC features relevant to the Equation of State (EOS) of isospin-asymmetric nuclear matter. We summarize empirical and theoretical properties of the single-nucleon momentum distribution $n(k)$, emphasizing the role of the neutron--proton tensor force, the dominance of correlated np pairs, and the enhancement of minority-species HMTs. Links to nucleon effective E-masses, quasi-deuteron components, and orbital entanglement are briefly noted. We examine how SRC-induced HMTs modify kinetic and potential contributions to the EOS in both non-relativistic and relativistic frameworks, including the softening of the kinetic symmetry energy and departures from the isospin parabolic approximation of asymmetric nuclear EOS. Sensitivity to high-momentum components and generalizations to arbitrary dimensions are also highlighted. Implications for heavy-ion reactions are summarized, including effects on particle yields, collective flows, deeply sub-threshold particle production and hard photon emission, driven by modified initial nucleon momentum distributions and abundant high relative-momentum np pairs during the reaction. Finally, we outline SRC-HMT consequences for neutron-star matter, covering proton fractions, tidal deformabilities, $Z$-factors, cooling, and the core--crust transition, as well as possible connections to dark-matter interactions in dense environments.