IMPROVING THE SIGNAL-TO-NOISE RATIO IN LATTICE GAUGE-THEORIES

Renormalization of composite fields is employed to suppress the statis tical noise in lattice gauge calculations. We propose a new action whi ch differs from the standard Wilson action by ''irrelevant'' operators , but suppresses the fluctuations of the plaquettes. We numerically st udy the Creutz ratios and find a scaling window. The SU(2) mass gap is estimated. We prove that the contributions of the ''irrelevant'' oper ators to the screening mass decrease towards the continuum limit. The results obtained from the action with noise suppression are compared w ith those of the standard Wilson action. [S0556-2821(97)01723-2].