SU(7) Unification of SU(3)_C*SU(4)_W* U(1)_{B-L}

We propose the SUSY SU(7) unification of the SU(3)_C* SU(4)_W* U(1)_{B-L} model. Such unification scenario has rich symmetry breaking chains in a five-dimensional orbifold. We study in detail the SUSY SU(7) symmetry breaking into SU(3)_C* SU(4)_W* U(1)_{B-L} by boundary conditions in a Randall-Sundrum background and its AdS/CFT interpretation. We find that successful gauge coupling unification can be achieved in our scenario. Gauge unification favors low left-right and unification scales with tree-level \sin^2\theta_W=0.15. We use the AdS/CFT dual of the conformal supersymmetry breaking scenario to break the remaining N=1 supersymmetry. We employ AdS/CFT to reproduce the NSVZ formula and obtain the structure of the Seiberg duality in the strong coupling region for 3/2N_c<N_F<3N_C. We show that supersymmetry is indeed broken in the conformal supersymmetry breaking scenario with a vanishing singlet vacuum expectation value.Comment: 25 pages, 1 figure

Finite SU(3)^3 model

We consider N=1 supersymmetric gauge theories based on the group SU(N)_1 x SU(N)_2 x ... x SU(N)_k with matter content (N,N*,1,...,1) + (1,N,N*,..., 1) + >... + (N*,1,1,...,N) as candidates for the unification symmetry of all particles. In particular we examine to which extent such theories can become finite, and find that a necessary condition is that there should be exactly three families. From phenomenological considerations an SU(3)^3 model is singled out. We consider an all-loop and a two-loop finite model based on this gauge group and we study their predictions concerning the third generation quark masses.Comment: 4 pages, 2 figures. Talk given at 17th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY09), Boston, USA, 5-10 June 200

Flavor from Strongly Coupled Supersymmetry

Strongly coupled supersymmetric theories can give rise to composite quarks and leptons at low energy. We show that the internal structure of these particles can explain the origin of three generations and provide a qualitative understanding of mass ratios and mixing angles between the different flavors of fermions, all within a renormalizable theory. The main point of the paper is to show how fermion masses and mixing angles can result from a ``dual'' Frogatt-Nielsen mechanism: fields neutral under $SU(3) \times SU(2) \times U(1)$ which carry flavor quantum numbers are confined within quarks and leptons, and from their perturbative interactions arises the observed flavor structure.Comment: 28 pages, 5 figures, LATEX. A few typos corrected and references adde

3D gauged supergravity from SU(2) reduction of N=1N=1 6D supergravity

We obtain Yang-Mills $SU(2)\times G$ gauged supergravity in three dimensions from $SU(2)$ group manifold reduction of (1,0) six dimensional supergravity coupled to an anti-symmetric tensor multiplet and gauge vector multiplets in the adjoint of $G$. The reduced theory is consistently truncated to $N=4$ 3D supergravity coupled to $4(1+\textrm{dim}\, G)$ bosonic and $4(1+\textrm{dim}\, G)$ fermionic propagating degrees of freedom. This is in contrast to the reduction in which there are also massive vector fields. The scalar manifold is $\mathbf{R}\times \frac{SO(3,\, \textrm{dim}\, G)}{SO(3)\times SO(\textrm{dim}\, G)}$, and there is a $SU(2)\times G$ gauge group. We then construct $N=4$ Chern-Simons $(SO(3)\ltimes \mathbf{R}^3)\times (G\ltimes \mathbf{R}^{\textrm{dim}G})$ three dimensional gauged supergravity with scalar manifold $\frac{SO(4,\,1+\textrm{dim}G)}{SO(4)\times SO(1+\textrm{dim}G)}$ and explicitly show that this theory is on-shell equivalent to the Yang-Mills $SO(3)\times G$ gauged supergravity theory obtained from the $SU(2)$ reduction, after integrating out the scalars and gauge fields corresponding to the translational symmetries $\mathbf{R}^3\times \mathbf{R}^{\textrm{dim}\, G}$.Comment: 24 pages, no figures, references added and typos correcte

N=8 matter coupled AdS_3 supergravities

Following the recent construction of maximal (N=16) gauged supergravity in three dimensions, we derive gauged D=3, N=8 supergravities in three dimensions as deformations of the corresponding ungauged theories with scalar manifolds SO(8,n)/(SO(8)x SO(n)). As a special case, we recover the N=(4,4) theories with local SO(4) = SO(3)_L x SO(3)_R, which reproduce the symmetries and massless spectrum of D=6, N=(2,0) supergravity compactified on AdS_3 x S^3.Comment: 11 pages, LaTeX2

Unification of Weak and Hypercharge Interactions at the TeV Scale

A realistic SU(3)_C x SU(3)_W unified theory is constructed with a TeV sized extra dimension compactified on the orbifold S_1/Z_2, leaving only the standard model gauge group SU(3)_C x SU(2)_L x U(1)_Y unbroken in the low energy 4D theory. The Higgs doublets are zero modes of bulk SU(3)_W triplets and serve to normalize the hypercharge generator, apparently giving a tree-level prediction for the weak mixing angle: \sin^2\theta = 1/4. The orbifold boundary conditions imply a restricted set of SU(3)_W gauge transformations: at an orbifold fixed point only the transformations of SU(2)_L x U(1)_Y are operative. This allows quarks to be located at this fixed point, overcoming the longstanding problem of how to incorporate matter in a unified SU(3)_W theory. However, in general this local, explicit breaking of SU(3)_W symmetry, necessary for including quarks into the theory, destroys the tree-level prediction for the weak mixing angle. This apparent contradiction is reconciled by making the volume of the extra dimension large, diluting the effects of the local SU(3)_W violation. In the case that the electroweak theory is strongly coupled at the cutoff scale of the effective theory, radiative corrections to the weak mixing angle can be reliably computed, and used to predict the scale of compactification: 1 - 2 TeV without supersymmetry, and in the region of 3 - 6 TeV for a supersymmetric theory. The experimental signature of electroweak unification into SU(3)_W is a set of ``weak partners'' of mass 1/2R, which are all electrically charged and are expected to be accessible at LHC. These include weak doublets of gauge particles of electric charge (++,+), and a charged scalar. When pair produced, they yield events containing multiple charged leptons, missing large transverse energy and possibly Higgs and electroweak gauge bosons.Comment: 13 pages, LaTeX, note added on charge quantizatio

Supersymmetry and Strongly Coupled Gauge Theories

I briefly review how supersymmetry helps in the extraction of exact nonperturbative information from field theories, and then discuss some open problems in strongly coupled gauge theories. (Talk given at ``30 Years of Supersymmetry'' symposium in Minneapolis, Minnesota on October 15, 2000.)Comment: 8 pages, 2 figure