相关论文: Witten's loop in the flipped SU(5) unification

We study the generation of neutrino masses in the $SU(3)_W$ electroweak unified theory in $M_4\times S_1/(Z_2\times Z'_2)$ spacetime. By appropriate orbifolding, the bulk symmetry $SU(3)_W$ is broken into $SU(2)_L \times U(1)_Y$ at one of…

We consider explicit unified models based on the flipped ${SU(5)\times U(1)}$ and $SU(6)\times SU(2)$ gauge groups in which gauge mediated proton decay operators are suppressed at leading order due to the special placement of matter fields…

In practically all extentions of the standard model, the neutrinos naturally acquire a mass. The neutrino mass matrix, however, contains many parameters which can neither be predicted by the prevailing models nor can be fitted to the data.…

We consider the problem of neutrino masses and mixing in the framework of flipped SU(5). The right-handed neutrino mass, generated through the operation of a seesaw mechanism by a sector of gauge singlets, leads naturally, at a subsequent…

We study models of neutrino masses which naturally give rise to an inverted mass hierarchy and bi-maximal mixing. The models are based on the see-saw mechanism with three right-handed neutrinos, which generates a single mass term of the…

The supersymmetric flipped $SU(6)\times U(1)$ gauge symmetry can arise through compactification of the ten dimensional $E_8\times E_8$ superstring theory. We show how realistic phenomenology can emerge from this theory by supplementing it…

This report is a review of the present status of GUT, especially renormalizable minimal SO(10) GUT, and its future prospect. It consists of two parts. In part I, I review how the minimal renormalizable supersymmetric SO(10) GUT, an SO(10)…

We revive Witten's mechanism for the radiative seesaw induced neutrino masses in SO(10) grand unified theory. We propose its extension to charged fermion masses as a possible cure for wrong tree level mass relations. We offer two simple…

In the past year, a new non-supersymmetric framework for electroweak symmetry breaking (with or without Higgs) involving SU(2)_L * SU(2)_R * U(1)_{B-L} in higher dimensional warped geometry has been suggested. In this work, we embed this…

I present two new renormalizable grand unified theories where the neutrino masses are generated through the type I and type III seesaw mechanisms. These theories can be considered as the simplest (SUSY) renormalizable grand unified theories…

We discuss systematically the fermion mass and mixing matrices in a generic \linebreak field-theoretical flipped $SU(5)$ model, with particular applications to neutrino and baryon number-changing physics. We demonstrate that the different…

A grand unified model based on SU(5) and supersymmetry is presented. Pairs of superfields belonging to 15 and 15* representations are newly introduced, while gauge coupling unification is satisfied. Improper mass relations in the minimal…

We discuss the simplest mechanisms for generating neutrino masses at tree level and one loop level. We find a significant number of new possibilities where one can generate neutrino masses at the one-loop level by adding only two new types…

We construct a simple SO(10) SUSY GUT with $D_3$ family symmetry and low energy R parity. The model describes fermion mass matrices with 14 parameters and gives excellent fits to 20 observable masses and mixing angles in both quark and…

We investigate the requirement of the existence of two degenerate vacua of the effective potential as a function of the Weinberg-Salam Higgs scalar field norm, as suggested by the multiple point principle, in an extension of the Standard…

We show that experimental results for the masses and mixing of the neutrinos can be understood naturally by a simple grand unification model of SU(5) coupled to N=1 supergravity. No right-handed neutrinos are included. The left-handed…

We provide a unified description of fermion masses and mixing angles in the framework of a supersymmetric grand unified SO(10) model with anarchic Yukawa couplings of order unity. The space-time is five dimensional and the extra flat…

I demonstrate that neutrino large mixing between $\nu_\mu$ and $\nu_\tau$ are naturally reproduced using a novel mechanism called `E-twisting'in a supersymmetric $E_6$ grand unification model. This model explains all the characteristic…

We review recent developments in theoretical models for neutrino masses and mixing. Emphases are given to models based on finite group family symmetries. In particular, we describe one recent model based on SU(5), in which both the…

We argue that the discovery of neutrino mass effects at Super-Kamiokande implies a clear logical chain leading from the Standard Model, through the MSSM and the recently developed Minimal Left Right Supersymmetric models with a…