All force and matter particles appear to be neutrino constructs with their associated time particles. Electron I guess is simplest example of matter...time particle 1/2 spin and three neutrinos....force particles two neutrino constructs with example of photons being what I think are two neutrinos with two 1/2 spin time particles. Gravitinos MIGHT be two neutrinos with two -1/2 spin time particles. These gravitinos might not exist in positive space...it might be that only photons can exist in positive space.