Related papers: Anomalous Wtb coupling effects in the weak radiati…
As a top-factory, the LHC is performing a direct study of top-quark anomalous FCNC couplings, which are, however, correlated closely with the rare B- and K-meson decays. In this paper, we study the effects of anomalous $tqZ$ (with $q=u,c$)…
We present a study of anomalous electroweak gauge-boson couplings which can be measured in e+e- and gamma gamma collisions at a future linear collider like ILC. We consider the gauge-boson sector of a locally SU(2) x U(1) invariant…
We simplify the general form of the fermion-fermion-gauge boson interactions generated by dimension-six gauge-invariant effective operators by using the equations of motion to remove redundant operators. It is found that the most general…
We explore the effects of the anomalous $tbW$ couplings on the $\bd$ mixing and recently measured $\bs$ mixing. The combined analysis of mixings via box diagrams with penguin decays provides strong constraints on the anomalous top quark…
We examine the sensitivity of flavor changing neutral current (FCNC) processes to anomalous triple gauge boson couplings. We show that in the non-linear realization of the electroweak symmetry breaking sector these processes are very…
Analytic expression for energy and angular dependence of a secondary charged lepton in the decay of a polarized top quark with anomalous $tWb$ couplings in the presence of all anomalous couplings are derived. The angular distribution of the…
We update the indirect bounds on anomalous triple gauge couplings coming from the non-universal one-loop contributions to the $Z \to b \bar{b}$ width. These bounds, which are independent of the Higgs boson mass, are in agreement with the…
Rare $B$-meson decays, suppressed in the Standard Model (SM) by the GIM mechanism, are sensitive probes of new physics. In particular, loop-level $b \to s$ transitions can reveal effects of heavy virtual particles such as vector-like quarks…
We update the standard model predictions for the branching ratios of the decays B -> (K,K*,Xs) l^+ l^-, with l=e,mu. Using the measurements of BR(B -> Xs gamma) and BR(B -> K l^+ l^-) as well as the upper limits on BR(B -> (K*,Xs) l^+…
We study the effects of an anomalous Z' boson on the anomalous magnetic moment of the muon (g-2), and especially the impact of its axial coupling. We mainly evaluate the negative contribution to (g-2) of such couplings at one-loop and look…
We have constructed a Monte Carlo generator for lowest-order predictions for the processes gamma gamma -> 4f and gamma gamma -> 4f+gamma in the Standard Model and extensions thereof by an effective gamma gamma Higgs coupling as well as…
Possible non-standard couplings which could contribute to the t -> b W process are studied based on the effective-Lagrangian approach. The corresponding effective Lagrangian consists of four kinds of dimension-6 effective operators, each of…
In this talk, we present the predictions for a number of radiative decays $B_{(s)}\to V\gamma$, with the vector meson in the final state, which proceed through the weak-annihilation mechanism. Within the factorization approximation, we take…
All lowest-order amplitudes for e+e- --> 4f+gamma are calculated including five anomalous quartic gauge-boson couplings that are allowed by electromagnetic gauge invariance and the custodial SU(2)_c symmetry. Three of these anomalous…
Parameterization of heavy effects beyond the Standard Model is available using higher-dimension operators of the effective field theory and their Wilson coefficients, where their values are not known. Experimental sensitivity to the Wilson…
We investigate the effects of anomalous neutral triple gauge couplings in $ZZ$ and $Z\gamma$ production processes, followed by the leptonic decay of the $Z$ boson, at a lepton collider with center-of-mass energy $\sqrt{s}=250$~GeV and…
We consider the possibility of studying anomalous contributions to the gamma-gamma-H and Z-gamma-H vertices through the process e-gamma--> e-H at future e-gamma linear colliders, with Sqrt(S)=500-1500 GeV. We make a model independent…
We present new direct constraints on a general $Wtb$ interaction using data corresponding to an integrated luminosity of 5.4 fb$^{-1}$ collected by the D0 detector at the Tevatron $p\bar{p}$ collider. The standard model provides a purely…
The production of three electroweak gauge bosons in high-energy $e^+e^-$ collisions offers a window on anomalous quartic gauge boson couplings. We investigate the effect of three possible anomalous couplings on the cross sections for…
We compute the complete two-loop O(alpha) Wilson coefficients relevant for radiative decays of the B meson in the SM. This is a necessary step in the calculation of the O(alpha alpha_s^n ln^n m_b/M_W) corrections and improves on our…