Canonical approach to finite density QCD with multiple precision computation

TL;DR

This paper employs a canonical approach with multiple precision computations to study finite density QCD, providing reliable thermodynamic observables at high baryon chemical potential and comparing favorably with reweighting methods.

Contribution

It introduces a canonical method with multiple precision calculations for finite density QCD, extending reliable results to higher chemical potentials.

Findings

Canonical method yields consistent thermodynamic observables with reweighting methods.

Reliable results obtained up to baryon chemical potential over temperature ratio of 3.

Multiple precision operations are crucial for accurate evaluation of canonical partition functions.

Abstract

We calculate the baryon chemical potential ($\mu_B$) dependence of thermodynamic observables, i.e., pressure, baryon number density and susceptibility by lattice QCD using the canonical approach. We compare the results with those by the multi parameter reweighting (MPR) method; Both methods give very consistent values in the regions where errors of the MPR are under control. The canonical method gives reliable results over $\mu_ B/T=3$,with $T$ being temperature. Multiple precision operations play an important roll in the evaluation of canonical partition functions.