Multiplicity, probabilities, and canonical sectors for the cold QCD matter

TL;DR

This paper investigates the properties of cold QCD matter at finite density using canonical partition functions derived from imaginary chemical potential, focusing on entropy measures and phase relations, especially in the large N_c limit.

Contribution

It introduces a method to analyze cold QCD matter properties via canonical partition functions without finite real chemical potential data, linking to the quarkyonic phase and ground state degeneracy.

Findings

Estimates of multiplicity and configuration entropy at finite density.

Clarification of the relation between canonical sectors and the quarkyonic phase.

Discussion of nontrivial ground state degeneracy in cold QCD matter.

Abstract

At sufficiently low temperature, without requiring any numerical data at finite real chemical potential, we can clarify the canonical partition function with fixed quark number via the imaginary chemical potential region with few ansatzs. The canonical partition function relates to the multiplicity distribution which can be observed in collider experiments and thus we may access important information of the properties of the QCD matter based on the canonical method. In this paper, we estimate the multiplicity entropy, the configuration entropy, and the pointwise information which can be calculable with the canonical partition function to understand the properties of the cold QCD matter at finite density. With the large $N_\mathrm{c}$ limit where $N_\mathrm{c}$ is the number of colors, we can simply estimate the tendency of them, and then the relation to the quarkyonic phase is clarified. In addition, we discuss the nontrivial ground state degeneracy from the viewpoint of the canonical sectors.