Spectrum of the pure glue theory

Abstract

This review is in two parts; it presents the status of the spectrum for the low-lying glueballs and the ('t Hooft) string tension in pure gauge theory. Part I compares numerical simulations of SU(2) lattice gauge theory with analytic (continuum) calculations in intermediate volumes. In particular it deals with the issues surrounding the T 2 + and E + glueballs. It also discusses a new zero-momentum effective Lagrangian, the analytic calculations for asymmetric volumes in relation with the deconfining temperature and the recent results for twisted boundary conditions. Part II outlines problems facing numerical simulations, which had brought progress to a standstill. It reviews methods which are aimed at mitigating these problems. Their implementation has recently yielded a wealth of results that are, by and large, quite consistent. Finally, this part tabulates “world averages” for the scalar and tensor glueballs, as determined in numerical simulations of pure lattice gauge theory.