9 research outputs found
Precision and uncertainties in mass scale predictions in SUSY SO(10) with SU(2)_L x SU(2)_R x U(1)_{B-L} x SU(3)_C intermediate breaking
In a class of SUSY SO(10) with
intermediate gauge symmetry, we observe that the
prediction on the unification mass is unaffected by
Planck-scale-induced gravitational and intermediate-scale-threshold effects,
although the intermediate scale itself is subject to such corrections.
In particular, without invoking the presence of additional lighter scalar
degrees of freedom but including plausible and reasonable threshold effects, we
find that interesting solutions for neutrino physics corresponding to
GeV and GeV are
permitted in the minimal models. Possibilities of low-mass right-handed gauge
bosons corresponding to TeV consistent with the CERN-LEP data
are pointed out in a number of models when threshold effects are included using
effective mass parameters.Comment: 12 pages including 7 tables (Typos corrected as per the published
version
High scale perturbative gauge coupling in R-parity conserving SUSY SO(10) with longer proton lifetime
It is well known that in single step breaking of R-parity conserving SUSY
SO(10) that needs the Higgs representations the GUT-gauge
coupling violates the perturbative constraint at mass scales few times larger
than the GUT scale. Therefore, if the SO(10) gauge coupling is to remain
perturbative up the Planck scale(=2x10^{18} GeV), the scale of GUT
symmetry breaking is to be bounded from below. The bound depends upon specific
Higgs representations used for SO(10) symmetry breaking but, as we find, can
not be lower than GeV. In order to obtain such high unification
scale we propose a two-step SO(10) breaking through
intermediate gauge
symmetry. We estimate potential threshold and gravitational corrections to the
running of gauge couplings and show that they can make the picture of
perturbative GUT- gauge coupling running consistent at least up to the Planck
scale. We also show that when by ,
gravitational corrections alone with negligible threshold effects may guarantee
such perturbative gauge coupling. The lifetime of the proton is found to
increase by nearly 6 orders over the current experimental limit for . For the proton decay mediated by dim.5 operator a wide range of
lifetimes is possible extending from the current experimental limit up to
values 2-3 orders longer.Comment: 11 pages epjc LaTex as per specifications of European Physical
Journal