The lattice QCD phase diagram in and away from the strong coupling limit

TL;DR

This paper explores the phase diagram of lattice QCD with four flavors of staggered quarks, using a strong-coupling expansion approach to bridge the gap between the strong and weak coupling limits, and presents initial results including the chiral critical point.

Contribution

It introduces a strong-coupling expansion method to study the QCD phase diagram approaching the continuum limit, providing new insights beyond the infinite coupling analysis.

Findings

Phase diagram including the chiral critical point derived from the expansion.

First results from the next-to-leading order expansion.

Demonstrates the potential of the approach to connect strong and weak coupling regimes.

Abstract

We study lattice QCD with four flavors of staggered quarks. In the limit of infinite gauge coupling, "dual" variables can be introduced, which render the finite-density sign problem mild and allow a full determination of the $\mu-T$ phase diagram by Monte Carlo simulations, also in the chiral limit. However, the continuum limit coincides with the weak coupling limit. We propose a strong-coupling expansion approach towards the continuum limit. We show first results, including the phase diagram and its chiral critical point, from this expansion truncated to next-to-leading order.