Ambar Ghosal

A4 symmetry and prediction of Ue3 in a modified Altarelli–Feruglio model

Abstract We show that a radiative modification of a recently proposed model by Altarelli and Feruglio with softly broken A 4 symmetry leads naturally to nonvanishing U e 3 with θ 13 ≃ 2 ° – 4 ° . The observed mass squared differences for solar and atmospheric neutrinos are reproduced, whereas the predicted solar neutrino mixing angle is brought down from the tri-bimaximal prediction to be in better agreement with the latest global analysis including experimental data from KamLAND and SNO.

Nonzero U{sub e3}, CP violation, and leptogenesis in a seesaw type softly broken A{sub 4} symmetric model

We have shown that nonzero U{sub e3} is generated in a seesaw type softly broken A{sub 4} symmetric model through a single parameter perturbation in m{sub D} in a single element. We have explored all possible 9 cases to study the neutrino mixing angles considering the best fitted values of {delta}m{sub {center_dot}}{sup 2} and {delta}m{sub atm}{sup 2} with all parameters real. We have extended our analysis for the complex case and demonstrated large low energy CP violation (J{sub CP}{approx_equal}10{sup -2}) and m{sub ee} in addition to mixing and mass pattern. We have also investigated leptogenesis and for a reasonable choice of model parameters compatible with low energy data, the Wilkinson Microwave Anisotropy Probe (WMAP) value of baryon asymmetry 6x10{sup -10} is obtained for right-handed neutrino mass scale M{sub 0}{approx_equal}10{sup 13} GeV. We have obtained a relation among the phases responsible for leptogenesis and have shown that those phases also have correlations with low energy CP violating phases.

Invited review: Physics potential of the ICAL detector at the India-based Neutrino Observatory (INO)

The upcoming 50 kt magnetized iron calorimeter (ICAL) detector at the India-based Neutrino Observatory (INO) is designed to study the atmospheric neutrinos and antineutrinos separately over a wide range of energies and path lengths. The primary focus of this experiment is to explore the Earth matter effects by observing the energy and zenith angle dependence of the atmospheric neutrinos in the multi-GeV range. This study will be crucial to address some of the outstanding issues in neutrino oscillation physics, including the fundamental issue of neutrino mass hierarchy. In this document, we present the physics potential of the detector as obtained from realistic detector simulations. We describe the simulation framework, the neutrino interactions in the detector, and the expected response of the detector to particles traversing it. The ICAL detector can determine the energy and direction of the muons to a high precision, and in addition, its sensitivity to multi-GeV hadrons increases its physics reach substantially. Its charge identification capability, and hence its ability to distinguish neutrinos from antineutrinos, makes it an efficient detector for determining the neutrino mass hierarchy. In this report, we outline the analyses carried out for the determination of neutrino mass hierarchy and precision measurements of atmospheric neutrino mixing parameters at ICAL, and give the expected physics reach of the detector with 10 years of runtime. We also explore the potential of ICAL for probing new physics scenarios like CPT violation and the presence of magnetic monopoles.

Baryon asymmetry from leptogenesis with four zero neutrino Yukawa textures

The generation of the right amount of baryon asymmetry

Lepton flavor violating Z decays in the Zee model

\eta

Constraining Scalar Singlet Dark Matter with CDMS, XENON and DAMA and Prediction for Direct Detection Rates

of the Universe from supersymmetric leptogenesis is studied within the type-I seesaw framework with three heavy singlet Majorana neutrinos

μτ symmetry, tribimaximal mixing and four zero neutrino Yukawa textures

N_i\,\,(i = 1,2,3)

A NEUTRINO MASS MODEL WITH REFLECTION SYMMETRY

and their superpartners. We assume the occurrence of four zeroes in the neutrino Yukawa coupling matrix

Probing deviations from tribimaximal mixing through ultrahigh energy neutrino signals

Y_\nu

Radiative neutrino mass matrix for three active plus one sterile species

, taken to be