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

Understand

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.