Group-Theoretical Classification of BPS States in D=4 Conformal   Supersymmetry: the Case of (1/N)-BPS
  In an earlier paper we gave the complete group-theoretical classification of BPS states of the N-extended D=4 conformal superalgebras su(2,2/N), but not all interesting cases were given in detail. In the present paper we spell out the interesting case of (1/N)-BPS and possibly protected states. 
V. K. Dobrev
hep-th math.RT