Clock model interpolation and symmetry breaking in O(2) models

Symmetry Breaking in Supersymmetric E6 Models

We study the electroweak and U(1) ′ symmetry breaking patterns in models with the particle content of supersymmetric E6, including standard model singlets S and exotic quarks D, D̄. Motivated by free fermionic string models, we do not require E6-type relations between Yukawa couplings. In particular, we assume that baryon and lepton numbers are conserved, so that the exotic quarks can be light. ...

Rotational Symmetry Breaking in Multi-Matrix Models

We consider a class of multi-matrix models with an action which is O(D)-invariant, where D is the number of N × N Hermitian matrices Xμ, μ = 1, . . . , D. The action is a function of all the elementary symmetric functions of the matrix Tμν = Tr(XμXν)/N . We address the issue whether the O(D) symmetry is spontaneously broken when the size N of the matrices goes to infinity. The phase diagram in ...

Radiative symmetry breaking in brane models

We propose a way to generate the electroweak symmetry breaking radiatively in non-supersymmetric type I models with string scale in the TeV region. By identifying the Higgs field with a tree-level massless open string state, we find that a negative squared mass term can be generated at one loop. It is finite, computable and typically a loop factor smaller than the string scale, that acts as an ...

Spontaneous R-Symmetry Breaking in O’Raifeartaigh Models

We study the question of whether spontaneous U(1)R breaking can occur in O’Raifeartaightype models of spontaneous supersymmetry breaking. We show that in order for it to occur, there must be a field in the theory with R-charge different from 0 or 2. We construct the simplest O’Raifeartaigh model with this property, and we find that for a wide range of parameters, it has a meta-stable vacuum whe...

About existence, symmetry and symmetry breaking for extremal functions of some interpolation functional inequalities