3 research outputs found
Yukawa coupling unification and non-universal gaugino mediation of supersymmetry breaking
The requirement of Yukawa coupling unification highly constrains the SUSY
parameter space. In several SUSY breaking scenarios it is hard to reconcile
Yukawa coupling unification with experimental constraints from B(b->s gamma)
and the muon anomalous magnetic moment a_mu. We show that b-tau or even t-b-tau
Yukawa unification can be satisfied simultaneously with b->s gamma and a_mu in
the non-universal gaugino mediation scenario. Non-universal gaugino masses
naturally appear in higher dimensional grand unified models in which gauge
symmetry is broken by orbifold compactification. Relations between SUSY
contributions to fermion masses, b->s gamma and a_mu which are typical for
models with universal gaugino masses are relaxed. Consequently, these
phenomenological constraints can be satisfied simultaneously with a relatively
light SUSY spectrum, compared to models with universal gaugino masses.Comment: 20 pages, 8 figures. References added. A copy of the paper with
better resolution figures can be found at
http://www.hep.fsu.edu/~balazs/Physics/Papers/2003
Dark Matter And With Minimal Soft SUSY Breaking II
We update and extend to larger masses our previous analysis of the MSSM with
minimal [MSOSM] soft SUSY breaking boundary conditions. We
find a well--defined, narrow region of parameter space which provides the
observed relic density of dark matter, in a domain selected to fit precision
electroweak data, including top, bottom and tau masses. The model is highly
constrained which allows us to make several predictions. We find the light
Higgs mass GeV and also upper bounds on the mass of the
gluino \mgluino\lsim3.1 TeV and lightest neutralino \mchi\lsim450 GeV. As
the CP odd Higgs mass increases, the region of parameter space consistent
with WMAP data is forced to larger values of and smaller values of
. Hence, we find an upper bound m_A \lsim 1.3 TeV. This in turn leads to
lower bounds on (assuming minimal
flavor violation) and on the dark matter spin independent detection cross
section \sigsip > 10^{-9} pb. Finally, we extend our previous analysis to
include WIMP signals in indirect detection and find prospects for WIMP
detection generally much less promising than in direct WIMP searches.Comment: 24 page
Dark Matter And With Minimal Soft SUSY Breaking
CMSSM boundary conditions are usually used when calculating cosmological dark
matter densities. In this paper we calculate the cosmological density of dark
matter in the MSSM using minimal soft SUSY breaking boundary
conditions. These boundary conditions incorporate several attractive features:
they are consistent with Yukawa unification, they result in a
"natural" inverted scalar mass hierarchy and they reduce the dimension 5
operator contribution to the proton decay rate. With regards to dark matter, on
the other hand, this is to a large extent an unexplored territory with large
squark and slepton masses , large and small . We find that in most regions of parameter space the cosmological density of
dark matter is considerably less than required by the data. However there is a
well--defined, narrow region of parameter space which provides the observed
relic density of dark matter, as well as a good fit to precision electroweak
data, including top, bottom and tau masses, and acceptable bounds on the
branching fraction of . We present predictions for Higgs
and SUSY spectra, the dark matter detection cross section and the branching
ratio in this region of parameter space.Comment: 15 pages, 5 figure