Low-energy parity restoration and unification mass scale within maximal symmetries

Abstract

We investigate the hierarchy of gauge boson masses in the maximal grand unified theory by studying the renormalization group equations for the running coupling constants associated with the symmetry breaking of SU(16)viaSU(12) q×SU(4) l×U(1) |B|−|L| chain. Particular attention is given to the contribution of Higgs scalars to these equations. It is found that the intermediate mass scale ML, associated with right-handed gauge bosons could be as low as 10 3 GeV only for sin 2θ w(M L) as high as 0.265 with α s(M L)=0.13. In this chain of symmetry breaking, we have also examined the lowest unification mass that is allowed by the low-energy data for sin 2θ w(M L) and the assumed gauge hierarchy. This has been done in two cases; first for the case where SU(3) c is vectorial, second, for the case where SU(3) c is axial. In both cases the lowest unification mass scales were found to be 10 13, 10 11, 10 8 and 10 7 GeV for sin 2θ w(M L) = 0.22, 0.24, 0.26,and0.265 respectively with α s(M L) = 0.13. The implication of these low unification masses on baryon non-conserving processes is also discussed.