220 research outputs found
BMO-estimation and Almost Everywhere Exponential Summability of Quadratic Partial Sums of Double Fourier Series
It is proved a -estimation for quadratic partial sums of two-dimensional
Fourier series from which it is derived an almost everywhere exponential
summability of quadratic partial sums of double Fourier series
Proton Stability In Supersymmetric SU(5)
Within supersymmetric SU(5) GUT we suggest mechanisms for suppression of
baryon number violating dimension five and six operators. The mechanism is
based on the idea of split multiplets (i.e. quarks and leptons are not coming
from a single GUT state) which is realized by an extension with additional
vector-like matter. The construction naturally avoids wrong asymptotic relation
. Thus, the long standing problems of the minimal SUSY
SU(5) GUT can be resolved.
In a particular example of flavor structure and with additional {\cal
U}(1)\tm {\cal Z}_{3N} symmetry we demonstrate how the split multiplet
mechanism works out. Namely, the considered model is compatible with successful
gauge coupling unification and realistic fermion mass pattern. The nucleon
decay rates are relatively suppressed and can be well compatible with current
experimental bounds.Comment: Discussions and some clarifications adde
Anomalous U(1)_A and Electroweak Symmetry Breaking
We suggest a new mechanism for electroweak symmetry breaking in the
supersymmetric Standard Model. Our suggestion is based on the presence of an
anomalous U(1)_A gauge symmetry, which naturally arises in the four dimensional
superstring theory, and heavily relies on the value of the corresponding
Fayet-Illiopoulos \xi-term.Comment: Latex, 11 pages, discussions and references adde
Model Building with Gauge-Yukawa Unification
In supersymmetric theories with extra dimensions, the Higgs and matter fields
can be part of the gauge multiplet, so that the Yukawa interactions can arise
from the gauge interactions. This leads to the possibility of gauge-Yukawa
coupling unification, g_i=y_f, in the effective four dimensional theory after
the initial gauge symmetry and the supersymmetry are broken upon orbifold
compactification. We consider gauge-Yukawa unified models based on a variety of
four dimensional symmetries, including SO(10), SU(5), Pati-Salam symmetry,
trinification, and the Standard Model. Only in the case of Pati-Salam and the
Standard Model symmetry, we do obtain gauge-Yukawa unification. Partial
gauge-Yukawa unification is also briefly discussed.Comment: 23 page
Sparticle mass spectra from SU(5) SUSY GUT models with Yukawa coupling unification
Supersymmetric grand unified models based on the gauge group SU(5) often
require in addition to gauge coupling unification, the unification of b-quark
and -lepton Yukawa couplings. We examine SU(5) SUSY GUT parameter space
under the condition of Yukawa coupling unification using 2-loop MSSM
RGEs including full 1-loop threshold effects. The Yukawa-unified solutions
break down into two classes. Solutions with low tan\beta ~3-11 are
characterized by gluino mass ~1-4 TeV and squark mass ~1-5 TeV. Many of these
solutions would be beyond LHC reach, although they contain a light Higgs scalar
with mass <123 GeV and so may be excluded should the LHC Higgs hint persist.
The second class of solutions occurs at large tan\beta ~35-60, and are a subset
of unified solutions. Constraining only unification to ~5%
favors a rather light gluino with mass ~0.5-2 TeV, which should ultimately be
accessible to LHC searches. While our unified solutions can be
consistent with a picture of neutralino-only cold dark matter, invoking
additional moduli or Peccei-Quinn superfields can allow for all of our
Yukawa-unified solutions to be consistent with the measured dark matter
abundance.Comment: 19 pages, 5 figures, 1 table, PDFLate
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