Search

If a Higgs field is conformally coupled to gravity, then it can give rise to the scale invariant density perturbations. We make use of this result in a realistic inert Higgs doublet model, where we have a pair of Higgs doublets conformally coupled to the gravity in the early universe. The perturbation of the inert Higgs is shown to be the scale invariant. This gives rise to the density perturbation observed through CMB by its couplings to the standard model Higgs and the subsequent decay. Loop corrections of this conformally coupled system gives rise to electroweak symmetry breaking. We constrain the couplings of the scalar potential by comparing with the amplitude and spectrum of CMB anisotropy measured by WMAP and this model leads to a prediction for the masses of the lightest Higgs and the other scalars. [ABSTRACT FROM AUTHOR]

The vacuum stability condition of the Standard Model (SM) Higgs potential with mass in the range of 124-127 GeV puts an upper bound on the Dirac mass of the neutrinos. We study this constraint with the right-handed neutrino masses up to TeV scale. The heavy neutrinos contribute to ΔL = 2 processes like neutrinoless double beta decay and same-sign-dilepton (SSD) production in the colliders. The vacuum stability criterion also restricts the light-heavy neutrino mixing and constrains the branching ratio (BR) of lepton flavor-violating process, like μ→eγ mediated by the heavy neutrinos. We show that neutrinoless double beta decay with a lifetime ~1025 years can be observed if the lightest heavy neutrino mass is <4.5 TeV. We show that the vacuum stability condition and the experimental bound on μ→e γ together put a constrain on heavy neutrino mass MR>3.3 TeV. Finally we show that the observation of SSDs associated with jets at the LHC needs much larger luminosity than available at present. We have estimated the possible maximum cross-section for this process at the LHC and show that with an integrated luminosity 100 fb-1 it may be possible to observe the SSD signals as long as MR < 400 GeV. [ABSTRACT FROM AUTHOR]

We show that a nonminimal coupling of electromagnetism with background torsion can produce birefringence of the electromagnetic waves. This birefringence gives rise to a B-mode polarization of the CMB. From the bounds on CMB polarization from QUaD experiment, one can put limits on the background torsion at ξ1Ti = (2.78 ± 4.85) × 10-20 GeV-1. [ABSTRACT FROM AUTHOR]

We study the generation of magnetic field in Higgs inflation models where the Standard Model Higgs boson has a large coupling to the Ricci scalar. We couple the Higgs field to the electromagnetic fields via a nonrenormalizable dimension six operator suppressed by the Planck scale in the Jordan frame. We show that by choosing the Higgs coupling λ(MZ) = 0.132 (which corresponds to mh = 126 GeV in keeping with the recent measurements by ATLAS and CMS) and curvature coupling ξ(MZ) = 103 we can generate comoving magnetic fields of 10-7 Gauss at present and comoving coherence length of 100 kpc. The problem of large back-reaction which is generic in the usual inflation models of magneto-genesis is avoided as the back-reaction is suppressed by the large Higgs-curvature coupling. [ABSTRACT FROM AUTHOR]