Nonlinear Symmetry and Unity of Spacetime and Matter∗

Based upon the invariances under the nonlinear global supersymmetry (NL SUSY) and the general coordinate transformation (GL(4, R)), a unified description of spacetime and matter is proposed. Except the graviton all elementary particles accomodated in a single irreducible representation of N = 10 extended super-Poincaré (SP) algebra are the composites of more fundamental objects superons with spin 1/2, which are Nambu–Goldstone (N–G) fermions accompnying the spontaneous breakedown of the global supertranslation of spacetime. The electroweak standard model (SM) and SU(5) (SO(10)) grand unified model (GUTs) are investigated systematically by using the superon diagrams. The stability of the proton, the suppression of the flavour changing neutral currents (FCNC), K0−K and B0−B mixings, CP-violation, the atmospheric νμ deficit, the charmless nonleptonic B decay and the absence of the electroweak lepton-flavor-mixing are understood naturally in the superon pictures of GUTs and some predictions are presented. The fundamental action of superon-graviton model (SGM) for supersymmetric spacetime and matter is obtained.