Thetexpansion and SU(2) lattice gauge theory

This paper presents the results obtained by applying the t expansion to the case of an SU(2) lattice gauge theory in 3+1 space-time dimensions. We compute the vacuum energy density, specific heat, string tension σ, mass M of the lowest-lying $0^{++}$ glueball, and the ratio R=$M^2$/σ. Our computations converge best for the energy density, specific heat, and R, and these quantities exhibit behavior which agrees with what we expect on general grounds and what is known from Euclidean Monte Carlo calculations. In particular we see a broad lump in the specific heat and determine √R to be √R =3.5±0.2, a value which lies in the ballpark of values obtained from Monte Carlo calculations. Our direct computations of the mass of the $0^{++}$ glueball and string tension cannot be easily compared to the results of Monte Carlo calculations, but appear to be consistent with what one would expect.