The Quark Pauli Principle and the Transmutation of Nuclear Matter

TL;DR

This paper investigates the quark phase space density in nuclei to identify a critical density where quark effects become dominant, suggesting a potential new framework for understanding nuclear matter.

Contribution

It introduces the concept of transmutation density based on quark phase space and estimates this density to be equal to normal nuclear matter density, linking quark effects to nuclear structure.

Findings

Quark phase space density exceeds unity at normal nuclear densities.

The transmutation density is approximately 0.17 fm^{-3}, matching nuclear matter density.

Implications for nuclear models and the role of quark degrees of freedom are discussed.

Abstract

The phase space density, $\rho^Q$, of quarks in nuclei is studied using realistic models of unintegrated quark distributions, known as transverse momentum densities (TMDs). If this density exceeds unity for matter at normal nuclear densities, the effects of the quark Pauli principle must play a role in nuclei, and models in which the nucleon density at low momentum is small (Quarkyonic matter) may become a starting point for an entirely new description of nuclei. We denote the nuclear density for which $\rho^Q=1$ to be a transmutation density, $n_T$, because quark degrees of freedom must be relevant at that density. Including the TMDs of [G. de Teramond et. al, \href{DOI:https://doi.org/10.1103/PhysRevLett.120.182001} Phys. Rev. Lett. {\bf 120}, 182002, (2018)] for the valence quarks and phenomenological TMDs for the sea quarks we find that $n_T=0.17 \pm 0.04\,\rm fm^{-3}$, the density of normal nuclear matter. Some of fhe implications of this finding are discussed.