Sourov Roy

Correlation between neutrino oscillations and collider signals of supersymmetry in an R-parity violating model

Motivated by the recent Super-Kamiokande results on atmospheric neutrinos, we incorporate massive neutrinos, with large angle oscillation between the second and third generations, in a scenario with R-parity violating supersymmetry. We emphasize the testability of such models through the observation of comparable numbers of muons and taus, produced together with the W-boson, in decays of the lightest neutralino. A distinctly measurable decay gap is another remarkable feature of such a scenario.

SOME IMPLICATIONS OF A SUPERSYMMETRIC MODEL WITH R-PARITY BREAKING BILINEAR INTERACTIONS

We investigate a supersymmetric scenario where R-parity is explicitly broken through a term bilinear in the lepton and Higgs superfields in the superpotential. We show that keeping such a term alone can lead to trilinear interactions, similar to those that are parametrized by λand λ ′ in the literature, involving the physical fields. The upper limits of such interactions are predictable from the constraints on the parameter space imposed by the lepton masses and the neutrino mass limits. It is observed that thus the resulting trilinear interactions are restricted to values that are smaller than the existing bounds on most of the λ-and λ ′ -parameters. Some phenomenological consequences of such a scenario are discussed.

Gauged Lμ−Lτ with large muon anomalous magnetic moment and the bimaximal mixing of neutrinos

Abstract We consider the gauging of L μ − L τ as an explanation of a possibly large muon anomalous magnetic moment. We then show how neutrino masses with bimaximal mixing may be obtained in this framework. We study the novel phenomenology of the associated gauge boson in the context of present and future high-energy collider experiments.

7 keV sterile neutrino dark matter in U(1) R -lepton number model

A bstractWe study the phenomenology of a keV sterile neutrino in a supersymmetric model with U(1)R-lepton number in the light of a very recent observation of an X-ray line signal at around 3.5 keV, detected in the X-ray spectra of Andromeda galaxy and various galaxy clusters including the Perseus galaxy cluster. This model not only provides a small tree level mass to one of the active neutrinos but also renders a suitable warm dark matter candidate in the form of a sterile neutrino with negligible active-sterile mixing. Light neutrino masses and mixing can be explained once one-loop radiative corrections are taken into account. The scalar sector of this model can accommodate a Higgs boson with a mass of ∼125 GeV. In this model gravitino is the lightest supersymmetric particle (LSP) and we also study the cosmological implications of this light gravitino with mass ∼OGeV

Effects of initial axion production and photon–axion oscillation on type Ia supernova dimming

\sim \mathcal{O}\left(\mathrm{GeV}\right)

Unusual Higgs boson signal in R-parity violating nonminimal supersymmetric models at the LHC

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Search for Higgs bosons in SUSY cascades in CMS and dark matter with non-universal gaugino masses

In an extension of the minimal supersymmetric standard model (popularly known as the μνSSM), three right handed neutrino superfields are introduced to solve the μ-problem and to accommodate the non-vanishing neutrino masses and mixing. Neutrino masses at the tree level are generated through R−parity violation and seesaw mechanism. We have analyzed the full effect of one-loop contributions to the neutrino mass matrix. We show that the current three flavour global neutrino data can be accommodated in the μνSSM, for both the tree level and one-loop corrected analyses. We find that it is relatively easier to accommodate the normal hierarchical mass pattern compared to the inverted hierarchical or quasi-degenerate case, when one-loop corrections are included.

Invisible Higgs decay in a supersymmetric inverse seesaw model with light sneutrino dark matter

Abstract Recently, Csaki, Kaloper and Terning (CKT) suggested that axion–photon oscillation in the intergalactic medium can explain the observed dimming of distant type Ia supernovae. This mechanism works only if the initial axion flux is much smaller than the initial photon flux. We study several mechanisms for such initial axion production. The direct axion production in the supernovae, the photon–axion oscillation in the magnetic field of supernovae and in the magnetic field of their host galaxies are addressed. We find it likely that the initial axion flux is very small and therefore does not pose a problem to the CKT mechanism.