Related papers: LEP1 vs. Future Colliders: Effective Operators And…
In this paper we consider a general $SU(2)_L\otimes SU(2)_R$ invariant Lagrangian describing scalar, vector and axial-vector resonances. By expanding the WW and the ZZ scattering amplitude up to the fourth order in the external momenta we…
In this note we expand on our previous study of the implications of LEP1 results for future colliders. We extend the effective operator-based analysis of De R\'ujula et al. to a larger symmetry group, and show at which cost their…
We analyze the constraints on vector leptoquarks coming from radiative corrections to $Z$ physics. We perform a global fitting to the LEP data including the oblique and non-universal contributions of the most general effective Lagrangian…
We obtain the constraints on scalar leptoquarks coming from radiative corrections to $Z$ physics. We perform a global fitting to the LEP data including the contributions of the most general effective Lagrangian for scalar leptoquarks, which…
We analyse the constraints on scalar leptoquarks coming from radiative corrections to $Z$ physics. We perform a global fitting to the LEP data including the contributions of the most general effective Lagrangian for scalar leptoquarks,…
An Effective Lagrangian description is useful for describing potential physics beyond the Standard Model. The method is illustrated by reference to interactions among the electroweak bosons ($W^\pm$ \& $Z^0$). The resulting estimates of the…
Taking into account the constraints from LEP1 and lower energy experiments, we identify the seven $SU(2)\times U(1)$ gauge invariant purely bosonic $dim=6$ operators which provide a quite general description of how New Physics could reflect…
In this paper we present updated constraints on the top-quark sector of the Standard Model Effective Field Theory using data available from Tevatron, LEP and the LHC. Bounds are obtained for the Wilson coefficients from a global fit…
From the viewpoint of the SU(2) coherent states (CS) and their path integrals (PI) labeled by a full set of Euler angles $(\phi, \theta, \psi)$ which we developed in the previous paper, we study the relations between gauge symmetries of…
We construct a manifestly gauge invariant Lagrangian in 3+1 dimensions for N Kaluza-Klein modes of an SU(m) gauge theory in the bulk. For example, if the bulk is 4+1, the effective theory is \Pi_{i=1}^{N+1} SU(m)_i with N chiral (\bar{m},m)…
We discuss experimental implications of extending the gauge structure of the Standard Model to include an additional U(1) interaction broken at or near the weak scale. We work with the most general, renormalizable Lagrangian for the…
We explore the potential of probing for a new neutral gauge boson that emerges from a topologically nontrivial structure of spacetime, focusing on its couplings to the fermions of the Standard Model. We analyze the current experimental…
We list all possible dim=6 CP conserving and SU(3)* SU(2)*U(1) gauge invariant interactions, which could be generated in case no new particles would be reachable in the future Colliders, and the only observable New Physics would be in the…
The model (Lagrangian) with a peculiar extra U(1)is clearly presented. The assigned extra U(1) gauge charges give a strong constraint to build Lagrangians. The Z' discovery limits are estimated and predicted at the Tevatron and the LHC. The…
The standard model for electroweak interactions uses the concepts of weak hypercharge and local gauge invariance of the Lagrangian density under the gauge group SU(2) x U(1). Taylor has remarked that U(1), being a multiply-connected group,…
We show that current experimental constraints already severely restrict what might be observable at $e\mu$ colliders. We identify some cases where it may be possible to probe physics beyond what might be possible at other facilities and…
A new anomaly-free gauged $U(1)_\ell$ lepton-number model is studied. Two standard model lepton generations acquire the same but oppositive sign $U(1)_\ell$ charges, while four exotic chiral leptons cancel the anomalies of the remaining…
In a model independent framework, the effects of new physics at the electroweak scale can be parametrized in terms of an effective Lagrangian expansion. Assuming the $SU(2)_L x U(1)_Y$ gauge symmetry is linearly realized, the expansion at…
In this work, I briefly report on constraints that can be obtained on new physics models that extend the scalar sector of the Standard Model (SM) of particle physics at the LHC. I concentrate on a few simple examples which serve to…
We present the results of a global analysis of a class of models with an extended electroweak gauge group of the form SU(2) x SU(2) x U(1), often denoted as G(221) models, which include as examples the left-right, the lepto-phobic, the…