Discriminating neutrino mass models using Type-II see-saw formula

Pramana

Mahadev Patagiri²  Mrinal Kumar Das³  N Nimal Singh1 2¹ 

[1] The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 31014 Trieste, Italy$$;Department of Physics, Cotton College, Guwahati 781 001, India$$;Department of Physics, Gauhati University, Guwahati 781 014, India$$

关键词: Neutrino mass models;    neutrino mixings;    see-saw mechanism;    solar neutrinos;    atmospheric neutrinos.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

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.

【 授权许可】

Unknown