Gauge action improvement and smearing Original Research Article

The effect of repeatedly smearing image gauge configurations is investigated. Six gauge actions (Wilson, Symanzik, Iwasaki, DBW2, Beinlich–Karsch–Laermann, Langfeld; combined with a direct image-overrelaxation step) and three smearings (APE, HYP, EXP) are compared. The impact on large Wilson loops is monitored, confirming the signal-to-noise prediction by Lepage. The fat-link definition of the “naive” topological charge proves most useful on improved action ensembles.