Dimensions of Supersymmetric Operators from AdS/CFT

We examine the AdS/CFT correspondence through a manifestly 5D supersymmetric formalism, corresponding to a 4D N=1 supersymmetric CFT. We find that the dimensions of scalar and fermionic component operators are simply related, and that there is a smooth transition of scalar operator dimensions through the value d_s = 2. By using this formalism, we also show that the formula used in the string literature for the dimension of fermion operators is incomplete.Comment: 11 page

The Higgs mass as a function of the compactification scale

We calculate to a few percent precision the Higgs potential in a model with supersymmetry broken by boundary conditions on an extra-dimension, compactified to a segment of length $L$, and a top quark quasi-localized on one of the two boundaries. 1/L alone, in the range 2-4 TeV, determines the Higgs mass, in the range 110-125 GeV, and the spectrum of gauginos, higgsinos and of the third-generation squarks. Lower values of 1/L cannot be excluded, with a progressive delocalization of the top quark.Comment: 22 pages, 6 figure

The Gaugephobic Higgs

We present a class of models that contains Randall-Sundrum and Higgsless models as limiting cases. Over a wide range of the parameter space WW scattering is mainly unitarized by Kaluza-Klein partners of the W and Z, and the Higgs particle has suppressed couplings to the gauge bosons. Such a gaugephobic Higgs can be significantly lighter than the 114 GeV LEP bound for a standard Higgs, or heavier than the theoretical upper bound. These models predict a suppressed single top production rate and unconventional Higgs phenomenology at the LHC: the Higgs production rates will be suppressed and the Higgs branching fractions modified. However, the more difficult the Higgs search at the LHC is, the easier the search for other light resonances (like Z', W', t', exotic fermions) will be.Comment: 20 pages, 3 figure

Radiative Electroweak Symmetry Breaking from a Quasi-Localized Top Quark

We consider 5D supersymmetric SU(3) x SU(2) x U(1) theories compactified at the TeV scale on S^1/Z_2 with supersymmetry broken by boundary conditions. Localizing the top quark at a boundary of a fifth dimension by a bulk mass term M_t, reduces the strength of radiative electroweak symmetry breaking. For M_t R approximately 1--2, the natural value for the top and bottom squark masses are raised to 500--1200 GeV, and all other superpartners may have masses of the compactification scale, which has a natural range of 1/R ~= 1.5--3.5 TeV. The superpartner masses depend only on 1/R, and are precisely correlated amongst themselves and with the mass of the Higgs boson, which is lighter than 130 GeV.Comment: 23 pages, 8 figures, Latex; typos correcte

Breaking the electroweak symmetry and supersymmetry by a compact extra dimension

We revisit in some more detail a recent specific proposal for the breaking of the electroweak symmetry and of supersymmetry by a compact extra dimension. Possible mass terms for the Higgs and the matter hypermultiplets are considered and their effects on the spectrum analyzed. Previous conclusions are reinforced and put on firmer ground.Comment: 25 pages, LaTeX, 9 eps figure

The AdS/CFT/Unparticle Correspondence

We examine the correspondence between the anti-de Sitter (AdS) description of conformal field theories (CFTs) and the unparticle description of CFTs. We show how unparticle actions are equivalent to holographic boundary actions for fields in AdS, and how massive unparticles provide a new type of infrared cutoff that can be simply implemented in AdS by a soft breaking of conformal symmetry. We also show that processes involving scalar unparticles with dimensions d_s<2 or fermion unparticles with dimensions d_f<5/2 are insensitive to ultraviolet cutoff effects. Finally we show that gauge interactions for unparticles can be described by bulk gauge interactions in AdS and that they correspond to minimal gauging of the non-local effective action, and we compute the fermion unparticle production cross-section.Comment: 26 pages, 1 figur

Supersymmetry and precision data after LEP2

We study one loop supersymmetric corrections to precision observables. Adding LEP2 e ebar --> f fbar cross sections to the data-set removes previous hints for SUSY and the resulting constraints are in some cases stronger than direct bounds on sparticle masses. We consider specific models: split SUSY, CMSSM, gauge mediation, anomaly and radion mediation. Beyond performing a complete one-loop analysis, we also develop a simple approximation, based on the Shat, That, W, Y `universal' parameters. SUSY corrections give W,Y > 0 and mainly depend on the left-handed slepton and squark masses, on M_2 and on mu.Comment: 16 page