5 research outputs found
Predictive fermion mass matrix ansatzes in non-supersymmetric SO(10) grand unification
We investigate the status of predictive fermion mass ansatzes which make use
of the grand unification scale conditions , , and in non-supersymmetric SO(10) grand unification.
The gauge symmetry below an intermediate symmetry breaking scale is
assumed to be that of the standard model with either one Higgs doublet or two
Higgs doublets . We find in both cases that a maximum of 5 standard model
parameters may be predicted within experimental ranges. We find that
the standard model scenario predicts the low energy to be in
a range which includes its experimental mid-value 0.044 and which for a large
top mass can extend to lower values than the range resulting in the
supersymmetric case. In the two Higgs standard model case, we identify the
regions of parameter space for which unification of the bottom quark and tau
lepton Yukawa couplings is possible at grand unification scale. In fact, we
find that unification of the top, bottom and tau Yukawa couplings is possible
with the running b-quark mass within the preferred range provided is near the low end of its allowed
range. In this case, one may make 6 predictions which include
within its confidence limits. However unless the running mass , third generation Yukawa coupling unification requires the top mass to be
greater thanComment: 30 pages, 8 figures available on request from
[email protected], Late