Physics at the Large Hadron Collider (LHC) and the International e + e − Linear Collider (ILC) will be complementary in many respects, as has been demonstrated at previous generations of hadron and lepton colliders. This report addresses the possible interplay between the LHC and ILC in testing the Standard Model and in discovering and determining the origin of new physics. Mutual benefits for the physics programme at both machines can occur both at the level of a combined interpretation of Hadron Collider and Linear Collider data and at the level of combined analyses of the data, where results obtained at one machine can directly influence the way analyses are carried out at the other machine. Topics under study comprise the physics of weak and strong electroweak symmetry breaking, supersymmetric models, new gauge theories, models with extra dimensions, and electroweak and QCD precision physics. The status of the work that has been carried out within the LHC / LC Study Group so far is summarised in this report. Possible topics for future studies are outlined.4

We consider extension of the standard model SU (2) l ×SU (2) h ×U (1) where the first two families of quarks and leptons transform according to the SU (2) l group and the third family according to the SU (2) h group. In this approach, the largeness of top-quark mass is associated with the large vacuum expectation value of the corresponding Higgs field. The model predicts almost degenerate heavy W ′ and Z ′ bosons with non-universal couplings, and extra Higgs bosons. We present in detail the symmetry breaking mechanism, and carry out the subsequent phenomenology of the gauge sector. We compare the model with electroweak precision data, and conclude that the extra gauge bosons and the Higgs bosons whose masses lie in the TeV range, can be discovered at the LHC.As we enter the era of the Large Hadron Collider (LHC), we anticipate the discovery of new physics (NP). In the past decade, we have witnessed many interesting theoretical proposals, each with its own variety of new particles beyond the standard model (SM).Several of these proposals require extra gauge bosons, for example, from a larger gauge group [1], from extension to higher dimensions [2] which leads to Kaluza-Klein type of mass ladders, or from non-commuting extended technicolor [3]. Extensions of SM with additional W 's and Z's that have non-universal couplings to quarks and leptons have also been considered. In this paper, we analyze a model with extra weak gauge bosons from the consideration of family structure.The electroweak (EW) gauge group of our model is SU (2) l and h stand for light and heavy families, respectively. The first two quark and lepton families are considered as light while the third as heavy. For each SU(2) gauge group, the chiral fermionic particles are the same as the SM particle contents and, therefore, the model is anomaly-free. In this framework, the large mass of the top quark is induced by a large vacuum expectation value (VEV) of one Higgs field responsible for SU(2) h breaking.A logical extension of the idea would have been to consider one SU(2) for each family.Such an idea has already been proposed some time back by Li and Ma where SU(2) for each generation was introduced [4]. With appropriate symmetry breaking patterns, the SU(2) l × SU(2) h × U(1) Y model can be produced. Later several authors have considered the same model and studied some consequences of this model [3,5,6]. Some low energy phenomenological [7] and cosmological [8] consequences have also been analyzed.The mechanism of generating the mass for the top and the Higgs structure in the abovementioned papers differ from our treatment here. The mechanism in the SU(2) l × SU(2) h × U(1) Y model that we are considering is a more conventional approach with an explicit Higgs structure. We shall first carry out the consequences of the breaking of symmetry, then study the Yukawa, gauge interactions and FCNC interactions in these sectors, and finally analyze the phenomenological consequences. Our study of the Higgs structure clarifies conditions necessary for the ligh...

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We compute the inclusive and differential cross sections for the associated production of a top quark along with a charged Higgs boson at hadron colliders to next-to-leading order (NLO) in perturbative quantum chromodynamics (QCD) and in supersymmetric QCD. For small Higgs boson masses we include top quark pair production diagrams with subsequent top quark decay into a bottom quark and a charged Higgs boson. We compare the NLO differential cross sections obtained in the bottom parton picture with those for the gluon-initiated production process and find good agreement. The effects of supersymmetric loop contributions are explored. Only the corrections to the Yukawa coupling are sizable in the potential discovery region at the CERN Large Hadron Collider (LHC). All expressions and numerical results are fully differential, permitting selections on the momenta of both the top quark and the charged Higgs boson.