274 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
Modelling of a compact anisotropic star as an anisotropic fluid sphere in gravity
In this paper, we have studied the new exact model of anisotropic star in
theory of gravity. The dynamical equations in theory with the
anisotropic fluid have been solved by using Krori-Barua solution. We have
determined that all the obtained solutions are free from central singularity
and potentially stable. The observed values of mass and radius of the different
strange stars RX J 1856-37, Her X-1, and Vela X-12 have been used to calculate
the values of unknown constants in Krori and Barua metric. The physical
parameters like anisotropy, stability and redshift of the stars have been
investigated in detail.Comment: Accepted in the Canadian Journal of Physic
Higgs Inflation, Quantum Smearing and the Tensor to Scalar Ratio
In cosmic inflation driven by a scalar gauge singlet field with a tree level
Higgs potential, the scalar to tensor ratio r is estimated to be larger than
0.036, provided the scalar spectral index n_s >= 0.96. We discuss quantum
smearing of these predictions arising from the inflaton couplings to other
particles such as GUT scalars, and show that these corrections can
significantly decrease r. However, for n_s >= 0.96, we obtain r >= 0.02 which
can be tested by the Planck satellite.Comment: 10 pages, 3 figures and 3 table
Sparticle Spectroscopy with Neutralino Dark matter from t-b-tau Quasi-Yukawa Unification
We consider two classes of t-b-tau quasi-Yukawa unification scenarios which
can arise from realistic supersymmetric SO(10) and SU(4)_C X SU(2)_L X SU(2)_R
models. We show that these scenarios can be successfully implemented in the
CMSSM and NUHM1 frameworks, and yields a variety of sparticle spectra with WMAP
compatible neutralino dark matter. In NUHM1 we find bino-higgsino dark matter
as well as the stau coannihilation and A-funnel solutions. The CMSSM case
yields the stau coannihilation and A-funnel solutions. The gluino and squark
masses are found to lie in the TeV range.Comment: 21 pages, 12 figures, 2 table
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
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