3 research outputs found
Updated Constraints on the Minimal Supergravity Model
Recently, refinements have been made on both the theoretical and experimental
determinations of the i.) mass of the lightest Higgs scalar (m_h), ii.) relic
density of cold dark matter in the universe (Omega_CDM h^2), iii.) branching
fraction for radiative B decay BF(b \to s \gamma), iv.) muon anomalous magnetic
moment (a_\mu), and v.) flavor violating decay B_s \to \mu^+\mu^-. Each of
these quantities can be predicted in the MSSM, and each depends in a
non-trivial way on the spectra of SUSY particles. In this paper, we present
updated constraints from each of these quantities on the minimal supergravity
(mSUGRA) model as embedded in the computer program ISAJET. The combination of
constraints points to certain favored regions of model parameter space where
collider and non-accelerator SUSY searches may be more focussed.Comment: 20 pages, 6 figures. Version published in JHE
Direct Detection of Dark Matter in Supersymmetric Models
We evaluate neutralino-nucleon scattering rates in several well-motivated
supersymmetric models, and compare against constraints on the neutralino relic
density, BF( b\to s\gamma ) as well as the muon anomalous magnetic moment a_\mu
. In the mSUGRA model, the indirect constraints favor the hyperbolic
branch/focus point (HB/FP) region of parameter space, and in fact this region
is just where neutralino-nucleon scattering rates are high enough to be
detected in direct dark matter search experiments! In Yukawa unified SUSY
SO(10) models with scalar mass non-universality, the relic density of
neutralinos is almost always above experimental bounds, while the corresponding
direct detection rates are below experimental levels. Conversely, in five
dimensional SO(10) models where gauge symmetry breaking is the result of
compactification of the extra dimension, and supersymmetry breaking is
communicated via gaugino mediation, the relic density is quite low, while
direct detection rates can be substantial.Comment: 25 page latex file including 18 EPS figures; revised version with
references added and cross sections rescaled; figures changed. A copy of the
paper with better resolution figures can be found at
http://www.hep.fsu.edu/~belyaev/projects/directz1
Updated Reach of the CERN LHC and Constraints from Relic Density, b->s gamma and a(mu) in the mSUGRA Model
{We present an updated assessment of the reach of the CERN LHC pp collider
for supersymmetric matter in the context of the minimal supergravity (mSUGRA)
model. In addition to previously examined channels, we also include signals
with an isolated photon or with a leptonically decaying Z boson. For an
integrated luminosity of 100 fb^{-1}, values of m_{1/2}\sim 1400 GeV can be
probed for small m_0, corresponding to a gluino mass of m_{\tg}\sim 3 TeV. For
large m_0, in the hyperbolic branch/focus point region, m_{1/2}\sim 700 GeV can
be probed, corresponding to m_{\tg}\sim 1800 GeV. We also map out parameter
space regions preferred by the measured values of the dark matter relic
density, the b\to s\gamma decay rate, and the muon anomalous magnetic moment
a_\mu, and discuss how SUSY might reveal itself in these regions. We find the
CERN LHC can probe the entire stau co-annihilation region and also most of the
heavy Higgs annihilation funnel allowed by WMAP data, except for some range of
large m_0 and m_{1/2} if \tan\beta \agt 50.Comment: 22 page latex file including 10 EPS figures; bug fix in relic density
code modifies figures in co-annihilation regio