Grand unification of fermion generations: Neutrino masses and cosmological constraints

1986 ◽  
Vol 33 (6) ◽  
pp. 1777-1784 ◽  
Author(s):  
D. Chang ◽  
A. Kumar ◽  
R. N. Mohapatra
2003 ◽  
Vol 18 (22) ◽  
pp. 3971-3979 ◽  
Author(s):  
S.M. BARR

A brief review is given of some ideas for explaining neutrino masses and mixings within the context of supersymmetric grand unification. Emphasis is put on so-called lopsided models.


2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Anjan S. Joshipura ◽  
Ketan M. Patel

Abstract Possibility of a Right-Handed (RH) neutrino being a Goldstone fermion of a spontaneously broken global U(1) symmetry in a supersymmetric theory is considered. This fermion obtains mass from the supergravity effects leading to a RH neutrino at the electroweak scale with a mass similar to the gravitino mass. A prototype model realizing this scenario contains just three gauge singlet superfields needed for the type I seesaw mechanism. Masses of the other two neutrinos are determined by the U(1) breaking scale which too can be around the electroweak scale. Light neutrinos obtain their masses in this scenario through (a) mixing with the RH neutrinos (type I seesaw), (b) mixing with neutralinos (R-parity breaking), (c) indirectly through mixing of the RH neutrinos with neutralinos, and (d) radiative corrections. All these contributions are described by the same set of a small number of underlying parameters and provide a very constrained and predictive framework for the neutrino masses which is investigated in detail for various choices of U(1) symmetries. It is found that flavour independent U(1) symmetries cannot describe neutrino masses if the soft supersymmetry breaking terms are flavour universal and one needs to consider flavour dependent symmetries. Considering a particular example of Lμ− Lτ symmetry, it is shown that viable neutrino masses and mixing can be obtained without introducing any flavour violation in the soft sector. The leptonic couplings of Majoron are worked out in the model and shown to be consistent with various laboratory, astrophysical and cosmological constraints. The neutrino data allows sizeable couplings between the RH neutrinos and Higgsinos which can be used to probe the pseudo-Goldstone fermion at colliders through its displaced decay vertex.


2013 ◽  
Vol 28 (05) ◽  
pp. 1350010 ◽  
Author(s):  
F. R. KLINKHAMER

It is pointed out (not for the first time) that the minimal Standard Model, without additional gauge-singlet right-handed neutrinos or isotriplet Higgs fields, allows for nonvanishing neutrino masses and mixing. The required interaction term is non-renormalizable and violates B-L conservation. The ultimate explanation of this interaction term may or may not rely on grand unification.


IFAE 2007 ◽  
2008 ◽  
pp. 265-270
Author(s):  
Alessandro Melchiorri ◽  
Francesco De Bernardis ◽  
Luca Pagano ◽  
Paolo Serra

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