Spontaneous Breaking of Global B-L Symmetry and Matter-Antimatter Oscillations in Grand Unified Theories

摘要

We explore the consequences of the hypothesis that B-L symmetry, which is exact in the standard model based on SU(2)sub(L) x U(1) x SU(3)sub(c) gauge group and its extension to the minimal SU(5) theory, is a spontaneously broken global symmetry. This results in possibly observable rates for delta (B-L)=0, delta B=2 hydrogen-antihydrogen transitions and double proton decay pp implies e exp + e exp + ( mu exp + mu exp + ) and delta (B-L)not=0, delta B=2 neutron-antineutron mixing and p+n implies pi 's, and furthermore, a relation between the transition time tausub(H-H-bar), tausub(n-n-bar), Majorana neutrino mass and a mass of a doubly charged Higgs particle delta exp ++ emerges. At the level of SU(2)sub(L) x U(1) x SU(3)sub(c), for tausub(n-n-bar)approx.=10 exp 7 sec and msub( delta ) exp ++ approx.=20 GeV, we predict tausub(H-H-bar)approx.=10 exp 3 yr and tausub(pp)approx.=10 exp 31 yr, both of which are experimentally stable numbers. The embedding of our model in SU(5) is discussed in detail, with the analysis of tausub(p) and sin exp 2 thetasub(W) besides matter oscillations. (Atomindex citation 14:774208)