Higher Loop Results for the Plaquette, Using the Clover and Overlap   Actions
  We calculate the perturbative value of the free energy in QCD on the lattice. This quantity is directly related to the average plaquette.   Our calculation is done to 3 loops using the clover action for fermions; the results are presented for arbitrary values of the clover coefficient, and for a wide range of fermion masses.   In addition, we calculate the 2 loop result for the same quantity, using the overlap action. 
A. Athenodorou, H. Panagopoulos, A. Tsapalis (University of Cyprus,   Nicosia)