Physical unitarity in the Lagrangian Sp(2)-symmetric formalism
  The structure of state vector space for a general (non-anomalous) gauge theory is studied within the Lagrangian version of the $Sp(2)$-symmetric quantization method. The physical {\it S}-matrix unitarity conditions are formulated. The general results are illustrated on the basis of simple gauge theory models. 
P.M. Lavrov and P.Yu. Moshin