Mikulas Gintner

Top-BESS model and its phenomenology

We introduce the top-BESS model which is the effective description of the strong electroweak symmetry breaking with a single new SU(2)_L+R triplet vector resonance. The model is a modification of the BESS model in the fermion sector. The triplet couples to the third generation of quarks only. This approach reflects a possible extraordinary role of the top quark in the mechanism of electroweak symmetry breaking. The low-energy limits on the model parameters found provide hope for finding sizable signals in the LHC Drell-Yan processes as well as in the s-channel production processes at the ILC. However, there are regions of the model parameter space where the interplay of the direct and indirect fermion couplings can hide the resonance peak in a scattering process even though the resonance exists and couples directly to top and bottom quarks.

The measurement of tri‐linear gauge boson couplings at e+e− colliders

We describe a detailed study of the process e+e−→lvlqq and the measurement of tri‐linear gauge boson couplings (TGV’s) at LEP200 and at a 500 GeV and 1 TeV NLC. We included all tree level Feynman diagrams contributing to the four‐fermion final states including gauge boson widths and non‐resonance contributions.We employed a maximum likelihood analysis of a five dimensional differential cross section of angular distributions. This approach appears to offer an optimal strategy for measurement of TGV’s. LEP200 will improve existing measurements of TGV’s but not enough to see loop contributions of new physics. Measurements at the NLC will be roughly 2 orders of magnitude more precise which would probe the effects of new physics at the loop level.

Measurement of the WWγ and WWZ couplings at LEP200: the benefits of higher energy?

Abstract We performed a detailed analysis of the process e + e − → lνq q ′ to determine its sensitivity to anomalous trilinear gauge boson couplings of the WWγ and WWZ vertices and how the sensitivity varies with energy and integrated luminosity. We included all tree level Feynman diagrams that contribute to this final state and used a maximum likelihood analysis of a five dimensional differential cross-section based on the W and W decay product angular distributions. For constant luminosity, increasing s from 175 GeV to 192 GeV (220 GeV) improves the measurement sensitivity by a factor of 1.5–2 (2–3) depending on the parameter measured. However, the lower luminosity expectd at higher s will reduce these improvements. In any case, the sensitivities for s =175 and L = 500 pb −1 of δg 1 z = ±0.22, δκ z = ±0.20, δκ γ = ±0.27, δL 9 l = ±5, and δL 9r = −230 +330 are likely to be at least an order of magnitude too big to see the effects of new physics.

The LHC Mass Limits for the SU(2)

In this paper, we derive the mass exclusion limits for the hypothetical vector resonances of a strongly interacting extension of the Standard model using the most recent upper bounds on the cross sections for various resonance production processes. The

_{\rm L+R}

SU(2)_{L+R}

Vector Resonance Triplet of a Strong Extension of the Standard Model

triplet of the vector resonances under consideration is embedded into the effective Lagrangian based on the non-linear sigma model with the

A modified BESS model as an effective description of the strong electroweak symmetry breaking

125

Resonances from Strongly-Interacting Electroweak Symmetry Breaking Sector at Future e+e- Colliders

-GeV

W-pair production in the process e+e--->l nu qq-bar' and measurement of the WW gamma and WWZ couplings.

SU(2)_{L+R}

A 125 GeV scalar improves the low-energy data support for the top-BESS model

scalar singlet. No direct interactions of the vector resonance to the SM fermions are assumed. We find that among eleven processes considered in this paper only those where the vector resonances decay to