PredictiveAnsatzfor fermion mass matrices in supersymmetric grand unified theories

1992 ◽  
Vol 45 (11) ◽  
pp. 4192-4200 ◽  
Author(s):  
Savas Dimopoulos ◽  
Lawrence J. Hall ◽  
Stuart Raby
Keyword(s):  
Fermion Mass ◽  
Grand Unified Theories ◽  
Mass Matrices ◽  
Unified Theories

scholarly journals A NEW ANSATZ FOR QUARK AND LEPTON MASS MATRICES

1992 ◽  
Vol 07 (26) ◽  
pp. 2429-2435 ◽  
Author(s):  
GIAN F. GIUDICE
Keyword(s):  
Vacuum Expectation ◽  
Cabibbo Angle ◽  
Expectation Values ◽  
Higgs Vacuum ◽  
Grand Unified Theories ◽  
Fermion Masses ◽  
Mass Matrices ◽  
Unified Theories ◽  
Free Parameters ◽  
Good Agreement

A new ansatz for quark and lepton mass matrices is proposed in the context of supersymmetric grand unified theories. The 13 parameters describing fermion masses and mixings are determined in terms of only 6 free parameters, allowing 7 testable predictions. The values of Vus, Vcb, Vub, mu, md, ms and mb are then predicted as a function of the 3 charged lepton masses, mc, mt and tan β, the ratio of Higgs vacuum expectation values. In particular the Cabibbo angle and ms/md are determined in terms of only lepton masses. All predictions are in very good agreement with experiments.

STRING-MOTIVATED GRAND UNIFIED THEORIES WITH HORIZONTAL GAUGE SYMMETRY

1994 ◽  
Vol 09 (30) ◽  
pp. 5369-5385 ◽  
Author(s):  
A.A. MASLIKOV ◽  
S.M. SERGEEV ◽  
G.G. VOLKOV
Keyword(s):  
Gauge Symmetry ◽  
Fermion Mass ◽  
Family Symmetry ◽  
Grand Unified Theories ◽  
Higher Dimensional ◽  
Unified Theories ◽  
Low Dimensional ◽  
Diagonal Subgroup ◽  
Higgs Fields ◽  
Level 2

In the framework of four-dimensional heterotic superstring with free fermions, we investigate the rank 8 grand unified string theories (GUST’s) which contain the SU(3) H gauge family symmetry. GUST’s of this type accommodate naturally the three fermion families presently observed and, moreover, can describe the fermion mass spectrum without high-dimensional representations of conventional unification groups. We explicitly construct GUST’s with gauge symmetry G= SU(5) × U(1) ×[ SU(3) × U(1) ]H ⊂ SO (16) in free complex fermion formulation. As the GUST’s originating from Kac-Moody algebras (KMA’s) contain only low-dimensional representations, it is usually difficult to break the gauge symmetry. We solve this problem by taking for the observable gauge symmetry the diagonal subgroup G sym of the rank 16 group G×G ⊂ SO(16) × SO(16) ⊂ E(8)×E(8). Such a construction effectively corresponds to a level 2 KMA, and therefore some higher-dimensional representations of the diagonal subgroup appear. This (due to G×G tensor Higgs fields) allows one to break GUST symmetry down to SU (3c)× U(1) em . In this approach the observed electromagnetic charge Q em can be viewed as a sum of two Q I and Q II charges of each G group. In this case, below the scale where G×G breaks down to G sym the spectrum does not contain particles with exotic fractional charges.

Symmetric versus antisymmetric mass matrices in grand unified theories

1980 ◽  
Vol 94 (3) ◽  
pp. 359-363 ◽  
Author(s):  
Aharon Davidson ◽  
Kameshwar C. Wali
Keyword(s):  
Grand Unified Theories ◽  
Mass Matrices ◽  
Unified Theories
Sign in / Sign up

Export Citation Format

Share Document