Thermodynamics of two-colour QCD

We discuss the thermodynamics of two-colour QCD with four flavours of stagg ered quarks on 8(3) x 4 and 16(3) x 4 lattices. In our simulations we use t he Naik action for the fermions and a (1,2) tree-level improved gauge actio n. We analyze the deconfinement and chiral phase transitions for four diffe rent quark masses (m=0.1,0.05,0.025,0.015). Contrary to three-colour QCD th e peak in the Polyakov loop susceptibility decreases with decreasing quark mass. This reflects an early breaking of the string in the heavy quark pote ntial, which we verify explicitly by calculating the heavy quark potential at finite temperature using Polyakov loop correlations.