Heavy dense QCD from a 3d effective lattice theory

TL;DR

This paper develops an effective lattice theory to study cold, dense QCD, reducing the sign problem and enabling analytical calculations that are consistent with simulations, thus advancing understanding of this challenging regime.

Contribution

It introduces an extended effective lattice theory for heavy dense QCD, enabling analytical calculations and expanding the convergence region of the expansion.

Findings

Analytical results agree with simulations.

Extension of the effective theory to higher order.

Resummation doubles the convergence region.

Abstract

The cold and dense regime of the QCD phase diagram is to this day inaccessible to first principle lattice calculations owing to the sign problem. Here we present progress of an ongoing effort to probe this particularly difficult regime utilising a dimensionally reduced effective lattice theory with a significantly reduced sign problem. The effective theory is derived by combined character and hopping expansion and is valid for heavy quarks near the continuum. We show an extension of the effective theory to order $u^5\kappa^8$ in the cold regime. A linked cluster expansion is applied to the effective theory resulting in a consistent mechanism for handling the effective theory fully analytically. The new results are consistent with the ones from simulations confirming the viability of analytic methods. Finally we resum the analytical result which doubles the convergence region of the expansion.