234 research outputs found
Higgs Boson Mass, Sparticle Spectrum and Little Hierarchy Problem in Extended MSSM
We investigate the impact of TeV-scale matter belonging to complete
vectorlike multiplets of unified groups on the lightest Higgs boson in the
MSSM. We find that consistent with perturbative unification and electroweak
precision data the mass m_h can be as large as 160 GeV. These extended MSSM
models can also render the little hierarchy problem less severe, but only for
lower values of m_h < 125 GeV. We present estimates for the sparticle mass
spectrum in these models.Comment: 27 pages, 14 figure
Non-Minimal Chaotic Inflation, Peccei-Quinn Phase Transition and non-Thermal Leptogenesis
We consider a phenomenological extension of the minimal supersymmetric
standard model (MSSM) which incorporates non-minimal chaotic inflation, driven
by a quadratic potential in conjunction with a linear term in the frame
function. Inflation is followed by a Peccei-Quinn phase transition, based on
renormalizable superpotential terms, which resolves the strong CP and mu
problems of MSSM and provide masses lower than about 10^12 GeV for the
right-handed (RH) (s)neutrinos. Baryogenesis occurs via non-thermal
leptogenesis, realized by the out-of-equilibrium decay of the RH sneutrinos
which are produced by the inflaton's decay. Confronting our scenario with the
current observational data on the inflationary observables, the light neutrino
masses, the baryon asymmetry of the universe and the gravitino limit on the
reheat temperature, we constrain the strength of the gravitational coupling to
rather large values (~45-2950) and the Dirac neutrino masses to values between
about 1 and 10 GeV.Comment: Final versio
Modeling of Kashmir Aftershock Decay Based on Static Coulomb Stress Changes and Laboratory-Derived Rate-and-State Dependent Friction Law
We model the spatial and temporal evolution of October 8, 2005 Kashmir earthquake\u2019s aftershock activity using the rate-and-state dependent friction model incorporating uncertainties in computed coseismic stress perturbations. We estimated the best possible value for frictional resistance \u2018\u2018Arn\u2019\u2019, background seismicity rate \u2018\u2018r\u2019\u2019 and coef\ufb01cient of stress variation \u2018\u2018CV\u2019\u2019 using maximum log-likelihood method. For the whole Kashmir earthquake sequence, we measure a frictional resistance Arn * 0.0185 MPa, r * 20 M3.7? events/year and CV = 0.94 \ub1 0.01. The spatial and temporal forecasted seismicity rate of modeled aftershocks \ufb01ts well with the spatial and temporal distribution of observed aftershocks that occurred in the regions with positive static stress changes as well as in the apparent stress shadow region. To quantify the effect of secondary aftershock triggering, we have re-run the estimations for 100 stochastically declustered catalogs showing that the effect of aftershock-induced secondary stress changes is obviously minor compared to the overall uncertainties, and that the stress variability related to uncertain slip model inversions and receiver mechanisms remains the major factor to provide a reasonable data \ufb01t
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