Discrete symmetries in the Kaluza-Klein-like theories
  In theories of the Kaluza-Klein kind there are spins or total angular moments in higher dimensions which manifest as charges in the observable $d=(3+1)$. The charge conjugation requirement, if following the prescription in ($3+1$), would transform any particle state out of the Dirac sea into the hole in the Dirac sea, which manifests as an anti-particle having all the spin degrees of freedom in $d$, except $S^{03}$, the same as the corresponding particle state. This is in contradiction with what we observe for the anti-particle. In this paper we redefine the discrete symmetries so that we stay within the subgroups of the starting group of symmetries, while we require that the angular moments in higher dimensions manifest as charges in $d=(3+1)$. We pay attention on spaces with even $d$. 
N.S. Mankoc Borstnik and H.B.F. Nielsen
hep-th hep-ph