Nucleon Effective Masses in Neutron-Rich Matter

TL;DR

This paper reviews recent progress in understanding various types of nucleon effective masses in neutron-rich matter, highlighting their importance in nuclear physics and astrophysics, and addressing longstanding debates in the field.

Contribution

It provides a comprehensive review of recent advances in the study of nucleon effective masses, especially in dense neutron-rich environments, clarifying their roles and implications.

Findings

Different isovector nucleon effective masses are used to characterize symmetry potentials.

Studies of short-range correlations help understand the E-mass in neutron-rich matter.

Recent progress addresses longstanding debates on nucleon effective masses.

Abstract

Various kinds of isovector nucleon effective masses are used in the literature to characterize the momentum/energy dependence of the nucleon symmetry potential or self-energy due to the space/time non-locality of the underlying isovector strong interaction in neutron-rich nucleonic matter. The multifaceted studies on nucleon isovector effective masses are multi-disciplinary in nature. Besides structures, masses and low-lying excited states of nuclei as well as nuclear reactions, studies of the isospin dependence of short-range correlations in nuclei from scatterings of high-energy electrons and protons on heavy nuclei also help understand nucleon effective masses especially the so-called E-mass in neutron-rich matter. A thorough understanding of all kinds of nucleon effective masses has multiple impacts on many interesting issues in both nuclear physics and astrophysics. We review some of the significant progresses made in recent years by the nuclear physics community in resolving some of the hotly debated and longstanding issues regarding nucleon effective masses especially in dense neutron-rich matter.