No Higgs Theory And Lepton Flavor Violating

Content:The Standard Model(SM) of elementary particle has achieved much success.However, the scalar sector suffers from the problems of too many free prameters,triviality and unnaturalness, etc.Therefore,the SM can only be an effective field theory below some high energy scale.There may be new physics beyond the SM.To completely avoid the problems arising from the elementary Higgs field in the SM,various models for dynamical electrowcak symmetry breaking(EWSB) have been proposed,among which the TC2 Model is attractive because it can not only explain the large top mass and but also provide a possible EWSB mechanism.Higgsless models do just what their name suggests:they break the elcctrowcak symmetry and unitarize the scattering of longitudinal W and Z bosons without employing a scalar Higgs boson.In this model,EWSB is encoded in the boundary conditions of the gauge fields.The simplest deconstructed Higgslcss model incorporates only three sites on the deconstructed lattice,which is called the three-site Higgslcss model.In this model,the ordinary fermions arc ideally dclocalized,which preserves the characteristic of vanishing precision electroweak corrections up to subleading order.Furthermore,the three-site Higgsless model is sufficiently rich to describe the physics associated with fermion mass generation,including the ordinary fcrmions and their heavy partners.There are two works in this paper.For the workâ… ,we study the possible signatures of new physics via some lepton flavor violating(LFV) processes:First,the contributions of the neutral top-pionÏ€_t⁰ and the non-universal gauge boson Z' predicted by topcolor scenario to the LFV semileptonicÏ„decaysτ→lP(V) are discussed.We find that the contributions of Z' to these decay processes are generally larger than those fromÏ€_t⁰.Ï„_t⁰ can only make the value of the branching ratio Br(τ→lP) in the range of 1×10^-11～1×10^-16,which is far below the sensitivity of foreseeable experiments.The non-universal gauge boson Z' can make the value of the branching ratio Br(Ï„^-→μ^-φ) reach 1×10^-7,which might approach the observable threshold of near-future experiments.For the work 11,we consider single production of the heavy top quark T predicted by the three site Higgslcss model in future high energy collider experiments.We will calculate the cross sections for single production of T in the high energy linear e⁺e^- coUider(ILC),the linear-ring type ep collider(THERA),and the CERN Large Hadron Collider(LHC).Some phcnomenological analysis are also given.Our numerical results show that its production cross sections at the e⁺e^- collider and the ep collidcr arc too small to be detected.However, the possible signals of T might be observed via the subprocess qb→qT at the LHC.