We study the fundamental-adjoint SU(2) lattice gauge theory in four dimensions by Monte Carlo simulations. We show that the string tension at the endpoint of the first-order line is finite. The endpoint is therefore not a second-order critical point of the traditional variety. We also measure the lattice Λ parameter from simulations along a line close to this endpoint and find Λ = (3.0 ± 0.3) × 10-3 σ. This disagrees from previous measurements for the pure fundamental Wilson theory by a factor of 4. Our results cast serious doubt on all continuum limit estimates made near quasi-critical and crossover regions.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics