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      Permanent link:
      https://www.ias.ac.in/article/fulltext/pram/066/02/0361-0375

    • Keywords

       

      Neutrino mass models; neutrino mixings; see-saw mechanism; solar neutrinos; atmospheric neutrinos

    • Abstract

       

      An attempt has been made to discriminate theoretically the three possible patterns of neutrino mass models,viz., degenerate, inverted hierarchical and normal hierachical models, within the framework of Type-II see-saw formula. From detailed numerical analysis we are able to arrive at a conclusion that the inverted hierarchical model with the same CP phase (referred to as Type [IIA]), appears to be most favourable to survive in nature (and hence most stable), with the normal hierarchical model (Type [III]) and inverted hierarchical model with opposite CP phase (Type [IIB]), follow next. The degenerate models (Types [IA,IB,IC]) are found to be most unstable. The neutrino mass matrices which are obtained using the usual canonical see-saw formula (Type I), and which also give almost good predictions of neutrino masses and mixings consistent with the latest neutrino oscillation data, are re-examined in the presence of the left-handed Higgs triplet within the framework of non-canonical see-saw formula (Type II). We then estimate a parameter (the so-called discriminator) which may represent the minimum degree of suppression of the extra term arising from the presence of left-handed Higgs triplet, so as to restore the good predictions on neutrino masses and mixings already acquired in Type-I see-saw model. The neutrino mass model is said to be favourable and hence stable when its canonical see-saw term dominates over the non-canonical (perturbative) term, and this condition is used here as a criterion for discriminating neutrino mass models.

    • Author Affiliations

       

      N Nimai Singh1 2 Mahadev Patgiri3 Mrinal Kumar Das2

      1. The Abdus Salam International Centre for Theoretical Physics, Strada Costiera, 11, Trieste - 31014, Italy
      2. Department of Physics, Gauhati University, Guwahati - 781 014, India
      3. Department of Physics, Cotton College, Guwahati - 781 001, India
    • Dates

       
  • Pramana – Journal of Physics | News

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