Related papers: Anomalous Weak Boson Couplings: Suggestions from U…
We report on a set of studies concerning the description of New Physics (NP) effects characterized by a scale much higher than the electroweak scale. We concentrate on the residual effects described by an effective lagrangian involving only…
We obtain the partial-wave unitarity constraints on dimension-six operators stemming from the analyses of vector boson and Higgs scattering processes as well as the inelastic scattering of standard model fermions into electroweak gauge…
We study that a minimal supersymmetric standard model with an extra $U(1)'$ gauge symmetry may accommodate the explicit CP violation at the one-loop level through radiative corrections. This model is CP conserving at the tree level and…
We examine a $SU(3)_c \otimes SU(3)_{L}\otimes U(1)$ gauge model which has a parity symmetric Lagrangian. The parity symmetry has the novel feature that it interchanges the gluons with the $SU(3)_L$ gauge bosons (which contain the ordinary…
We study the physics potential of the 8 TeV LHC to discover signals of extended gauge models or extra dimensional models whose low energy behavior is well represented by an SU(2) x SU(2) x U(1) electroweak gauge structure. We find that with…
We introduce a physical scalar sector in a SU(2)xU(1) electroweak theory in which the gauge group is realized non linearly. By invoking theoretical as well as experimental constraints, we build a phenomenologically viable model in which a…
We investigate CP violating 2 Higgs doublet models as an effective theory emerging from models with an $SU(3)_L \otimes U(1)_X$ gauge symmetry. Because of the extension of the electroweak symmetry, a characteristic structure of Yukawa…
We review and update current limits on possible anomalous couplings of the top quark to gauge bosons. We consider data from top quark decay (as encoded in the $W$-boson helicity fractions) and single-top production (in the $t$-, $s$- and…
Using an effective field theory approach, we study the new physics (NP) corrections to muon and beta decays and their effects on the extractions of V_ud and V_us. Assuming nearly flavor blind NP interactions we find that the CKM-unitarity…
Using asymptotic helicity amplitudes for Vector-Vector, Vector-Higgs and Higgs-Higgs scattering, we establish the unitarity constraints on the $SU(2)_c$ conserving and $W_\mu$ depending interactions, which at sufficiently high energies may…
If electro-weak symmetry is broken by a new strongly interacting sector, new physics will probably manifest itself in gauge boson scattering at the LHC. The relevant dynamics is well described in terms of an effective lagrangian. We discuss…
One of the much-debated novel features of theories with extra dimensions is the presence of power-like loop corrections to gauge coupling unification, which have the potential of allowing a significant reduction of the unification scale. A…
We investigate CP-violating effects in electroweak interactions at future high-energy muon colliders within the Standard Model Effective Field Theory (SMEFT) framework. Focusing on four dimension-six CP-odd operators -- $…
We study new physics effects to the quartic gauge boson couplings formulated by the electroweak chiral Lagrangian. Five next-to-leading order operators characterize the anomalous quartic gauge interactions which involve pure Goldstone boson…
We develop a perturbative framework with which to discuss departures from exact Lorentz invariance and explore their potentially observable ramifications. Tiny non-invariant terms introduced into the standard model Lagrangian are assumed to…
We explore the sensitivity of future muon colliders to CP-violating interactions in the Higgs sector, specifically focusing on the process $\mu^- \mu^+ \to h \bar{\nu_{l}} \nu_{l} \to b\bar{b} \bar{\nu_{l}}\nu_{l}$. Using a…
I build a SU(2)left x U(1) electroweak gauge theory of J=0 mesons, which transform like sets of fermion-antifermion composite fields. SU(2)left x U(1) is embedded in a natural way, compatible with the Glashow-Salam-Weinberg model for…
We derive perturbativity constraints on beyond standard model scenarios with extra gauge groups, such as $SU(2)$ or $U(1)$, whose generators contribute to the electric charge, and show that there are both upper and lower limits on the…
We discuss the parameterization for electroweak gauge boson interactions without a light Higgs boson. We present the constraints on the anomalous gauge-boson couplings from the current experiments. We emphasize that the four-point couplings…
The form of collinear gauge invariance for power suppressed operators in the soft-collinear effective theory is discussed. Using a field redefinition we show that it is possible to make any power suppressed ultrasoft-collinear operators…