Continuous Time Monte Carlo for Lattice QCD in the Strong Coupling Limit

TL;DR

This paper introduces a continuous time Monte Carlo method for lattice QCD in the strong coupling limit, eliminating the need for continuum extrapolation and improving computational efficiency while resolving the sign problem.

Contribution

The authors develop a worm-type Monte Carlo algorithm with continuous Euclidean time for lattice QCD at infinite gauge coupling, avoiding continuum extrapolation and reducing computational complexity.

Findings

No continuum extrapolation needed for N_tau -> infinity

Algorithm is faster and sign problem is eliminated

Phase diagram determined as a function of temperature and chemical potential

Abstract

We present results for lattice QCD in the limit of infinite gauge coupling, obtained from a worm-type Monte Carlo algorithm on a discrete spatial lattice but with continuous Euclidean time. This is obtained by sending both the anisotropy parameter gamma^2 \sim a/a_t and the number of time-slices N_\tau to infinity, keeping the ratio \gamma^2/N_\tau \sim aT fixed. The obvious gain is that no continuum extrapolation N_\tau -> \infty has to be carried out. Moreover, the algorithm is faster and the sign problem disappears. We compare our computations with those on discrete lattices. We determine the phase diagram as a function of temperature and baryon chemical potential.