Vacuum energy in some particular quantum field theories
  We study the properties of a class of quantum field theories endowed with an equal number of anti commuting and commuting field variables, the most common example being the supersymmetric models. Based on the scaling properties of the partition function we find that these theories have the quantum energy momentum tensor associated to dilatations and thus the vacuum energy equal to zero. 
Renata Jora
hep-ph hep-th