THE SPECTRUM OF THE 2-DIMENSIONAL GAUGE ISING-MODEL(1)

We present a high precision Monte Carlo study of the spectrum of the Z (2) gauge theory in 2 + 1 dimensions in the strong coupling phase. Usi ng state-of-the-art Monte Carlo techniques we are able to accurately d etermine up to three masses in a single channel. We compare our result s with the strong coupling expansion for the lightest mass and with re sults for the universal ratio sigma/m(2) determined for the phi(4) the ory. Finally the whole spectrum is compared with that obtained from th e Isgur-Paton flux-tube model and the spectrum of the 2 + 1-dimensiona l SU(2) gauge theory, A remarkable agreement between the Ising and SU( 2) spectra (except for the lowest mass state) is found.