Particle theory

Abstract:

We study the approach to the continuum limit of SU(2) lattice gauge theory by accurately calculating several physical quantities on lattices up to 204 and for couplings up to β=4/g2=2.6. We find that the dependence of mass ratios on the lattice spacing weakens as the spacing decreases, although the two-loop relation between the spacing and g2 is not yet attained for β≤2.6. We find glueball masses, and the string tension to be roughly in the ratio m(2-):m(0-):m(2+):m(0+):√K≈7:6.5:5.5:3.8:1 for the smallest lattice spacings. © 1987.

Abstract:

We use fuzzy Wilson loops on lattices of different spatial size to study the glueball spectrum. Accurate results on 0+ and 2+ states for SU(2) of colour are reported here. © 1987.

Abstract:

We calculate 0+ and 2+ correlation functions using an improved method. On small physical volumes we reproduce the result, m(0+)≈m(2+), recently obtained by other methods. However, we also obtain evidence that for larger physical volumes the 2+ is heavier than the 0+: m(2+) m(0+)≈ 5 3. © 1987.

Abstract:

We present a simple iterative method for obtaining glueball wave functionals of the appropriate physical size as one decreases the lattice spacing. We test the method in SU (2) for 2.1 ≤ β ≤ 2.5 and find a gain in computer time over previous methods, that can be several orders of magnitude. The method appears to make possible reliable, large lattice calculations of excited glueball masses and significantly extends the range of bare couplings where reliable glueball calculations can be performed. © 1987.