We show that the supersymmetric extension of the Standard Model modifies the structure of the low lying BFKL discrete pomeron states (DPS) which give a sizable contribution to the gluon structure function in the HERA x and Q2 region. The comparison of the gluon density, determined within DPS with N=1 SUSY, with data favours a supersymmetry scale of the order of 10 TeV. The DPS method described here could open a new window to the physics beyond the Standard Model.
In this talk, I present a new framework to understand the long-standing fermion mass hierarchy puzzle. We extend the Standard Model gauge symmetry by an extra local U(1)_S symmetry, broken spontaneously at the electroweak scale. All the SM particles are singlet with respect to this U(1)_S. We also introduce additional flavor symmetries, U(1)_Fs, with flavon scalars F_i, as well as vectorlike quarks and leptons at the TeV scale. The flavon scalars have VEV in the TeV scale. Only the top quark has the usual dimension four Yukawa coupling. EW symmetry breaking to all other quarks and leptons are propagated through the messenger field, S through their interactions involving the heavy vector-like fermions and S, as well as through their interactions involving the vector-like fermions and F_i. In addition the explaining the hierarchy of the charged fermion masses and mixings, the model has several interesting predictions for Higgs decays, flavor changing neutral current processes in the top and the b quark decays, decays of the new singlet scalars to the new Z boson, as well as productions of the new vectorlike quarks. These predictions can be tested at the LHC.
This is a short review about relations between new scalars and mechanisms to generate neutrino masses. We investigate leptohilic scalars whose Yukawa interactions are only with leptons. We discuss possibilities that measurements of their leptonic decays provide information on how neutrino masses are generated and on parameters in the neutrino mass matrix (e.g. the lightest neutrino mass).
Gauge coupling unification and the stability of the Higgs vacuum are among two of the cherished features of low-energy supersymmetric models. Putting aside questions of naturalness, supersymmetry might only be realised in nature at very high energy scales. If this is the case, the preservation of gauge coupling unification and the stability of the Higgs vacuum would certainly require new physics, but it need not necessarily be at weak scale energies. New physics near the unification scale could in principle ensure Grand Unification, while new physics below $mu sim 10^{10}$ GeV could ensure the stability of the Higgs vacuum. Surprisingly however, we find that in the context of a supersymmetric SO(10) Grand Unified Theory, gauge coupling unification and the Higgs vacuum stability, when taken in conjunction with existing phenomenological constraints, require the presence of $mathcal{O}$(TeV)-scale physics. This weak-scale physics takes the form of a complex scalar SU(2)$_L$ triplet with zero hypercharge, originating from the $mathbf{210}$ of SO(10).
We present a collection of signatures for physics beyond the standard model that need to be explored at the LHC. First, are presented various tools developed to measure new particle masses in scenarios where all decays include an unobservable particle. Second, various aspects of supersymmetric models are discussed. Third, some signatures of models of strong electroweak symmetry are discussed. In the fourth part, a special attention is devoted to high mass resonances, as the ones appearing in models with warped extra dimensions. Finally, prospects for models with a hidden sector/valley are presented. Our report, which includes brief experimental and theoretical reviews as well as original results, summarizes the activities of the New Physics working group for the Physics at TeV Colliders workshop (Les Houches, France, 8-26 June, 2009).
We present a collection of signatures for physics beyond the standard model that need to be explored at the LHC. The signatures are organized according to the experimental objects that appear in the final state, and in particular the number of high pT leptons. Our report, which includes brief experimental and theoretical reviews as well as original results, summarizes the activities of the New Physics working group for the Physics at TeV Colliders workshop (Les Houches, France, 11-29 June, 2007).