1998

Ph.D

University of Madras

This thesis makes a systematic analyses of the solar and the atmospheric neutrino problems in a single framework in which all the three flavors of neutrinos can mix with each other. The region which is allowed by solar and atmospheric neutrino data in the three neutrino parameter space is mapped out. It is shown that one gets bounds on all the five parameters which control the oscillations. Novel effects of Neutrino oscillations such as the day-night asymmetry observable in the real time solar neutrino detectors. The possible enhancement of the solar neutrino counting rate during a solar eclipse is analyzed. It shown how these can constrain the neutrino parameter space mapped out previously. It is a fact that neutrinos are massive as these effects can occur only if neutrinos oscillate. Taking the constraints coming from terrestrial experiments into account and showing that this can drastically reduce the allowed region in the three flavor parameter space, this thesis gives an estimate of the contribution of various channel of oscillations to different experiments. Various concepts such as the 'Solar neutrino problem', the 'atmospheric neutrino problem', 'novel effects of neutrino oscillations', Terrestrial experiments and future experiments are discussed in detail in this thesis.