Preon Model and Family Replicated E_6 Unification

Previously we suggested a new preon model of composite quark-leptons and bosons with the 'flipped' $E_6\times \widetilde{E_6}$ gauge symmetry group. We assumed that preons are dyons having both hyper-electric $g$ and hyper-magnetic $\tilde g$ charges, and these preons-dyons are confined by hyper-magnetic strings which are an ${\bf N}=1$ supersymmetric non-Abelian flux tubes created by the condensation of spreons near the Planck scale. In the present paper we show that the existence of the three types of strings with tensions $T_k=k T_0$ $(k = 1,2,3)$ producing three (and only three) generations of composite quark-leptons, also provides three generations of composite gauge bosons ('hyper-gluons') and, as a consequence, predicts the family replicated $[E_6]^3$ unification at the scale $\sim 10^{17}$ GeV. This group of unification has the possibility of breaking to the group of symmetry: $[SU(3)_C]^3\times [SU(2)_L]^3\times [U(1)_Y]^3 \times [U(1)_{(B-L)}]^3$ which undergoes the breakdown to the Standard Model at lower energies. Some predictive advantages of the family replicated gauge groups of symmetry are briefly discussed.Comment: This is a contribution to the Proc. of the Seventh International Conference ''Symmetry in Nonlinear Mathematical Physics'' (June 24-30, 2007, Kyiv, Ukraine), published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA

Seesaw scales and the steps from the Standard Model towards superstring-inspired flipped E_6

Recently in connection with Superstring theory E_8 and E_6 unifications became very promising. In the present paper we have investigated a number of available paths from the Standard Model (SM) to the E_6 unification, considering a chain of flipped models following the extension of the SM: SU(3)_C\times SU(2)_L\times U(1)_Y \to SU(3)_C\times SU(2)_L\times U(1)_X \times U(1)_Z \to SU(5)\times U(1)_X \to SU(5)\times U(1)_{Z1} \times U(1)_{X1} \to SO(10) \times U(1)_{X1} \to SO(10) \times U(1)_{Z2}\times U(1)_{X2} \to E_6\times U(1)_{X2} or E_6, Also we have considered a chain with a left-right symmetry: SU(3)_C\times SU(2)_L\times U(1)_Y \to SU(3)_C\times SU(2)_L \times SU(2)_R\times U(1)_X\times U(1)_Z \to SU(4)_C\times SU(2)_L \times SU(2)_R\times U(1)_Z \to SO(10)\times U(1)_Z \to E_6. We have presented four examples including non-supersymmetric and supersymmetric extensions of the SM and different contents of the Higgs bosons providing the breaking of the flipped SO(10) and SU(5) down to the SM. It was shown that the final unification E_6\times U(1) or E_6 at the (Planck) GUT scale M_{SSG} depends on the number of the Higgs boson representations considered in theory.Comment: 25 pages, 7 figure

Implementation of the Multiple Point Principle in the Two-Higgs Doublet Model of type II

The multiple point principle (MPP) is applied to the non--supersymmetric two-Higgs doublet extension of the Standard Model (SM). The existence of a large set of degenerate vacua at some high energy scale caused by the MPP results in a few relations between Higgs self-coupling constants which can be examined at future colliders. The numerical analysis reveals that these MPP conditions constrain the mass of the SM--like Higgs boson to lie below 180 GeV for a wide set of MPP scales $\Lambda$ and $\tan\beta$.Comment: 26 pages, 3 figures, some minor changes to the tex