Related papers: New Tensor Interactions and the $K_L$-$K_S$ Mass D…
A minimal extension of the Standard Model containing the four-color quark-lepton symmetry is proposed and discussed. The existence of a rather light extra $Z'$-boson originated from the four-color quark-lepton symmetry is shown to be…
A complete set of dimension-6 effective contact interactions involving Higgs, gauge bosons and quarks is studied. Limits on the coefficients of these new operators are obtained from the experimental values of the $Z$ and $W$ gauge bosons…
Gauge invariance is a powerful tool to determine the dynamics of the electroweak and strong forces. The particle content, structure and symmetries of the Standard Model Lagrangian are discussed. Special emphasis is given to the many…
Gauge invariance is a powerful tool to determine the dynamics of the electroweak and strong forces. The particle content, structure and symmetries of the Standard Model Lagrangian are discussed. Special emphasis is given to the many…
We discuss properties of QCD with variable and large $N_c$, taking into account electroweak interactions; i.e., we analyze the generalization of the standard model based on the gauge group $G={\rm SU}(N_c) \times {\rm SU(2)}_L \times {\rm…
We calculate electromagnetic mass difference of mesons using a method proposed by Duncan {\it et al}. The RG-improved gauge action and the non-compact Abelian gauge action are employed to generate configurations. Quark propagators in the…
Recent measurements at the Large Hadron Collider allow for a robust and precise characterisation of the electro-weak interactions of the top quark. We present the results of a global analysis at next-to-leading order precision including…
We examine new aspects of leptoquark (LQ) phenomenology using effective field theory (EFT). We construct a complete set of leading effective operators involving SU(2) singlets scalar LQ and the SM fields up to dimension six. We show that,…
We propose an $SU(3)_C\times SU(2)_L\times U(1)_{Y}\times U(1)_{B-L}$ model, in which the neutrino masses and mixings can be generated via Type-I seesaw mechanism after $U(1)_{B-L}$ breaking. A light mediator emerges and enables…
Detailed numerical analysis of four charged leptons photoproduction in frame of standard theory of electroweak interaction is presented. Total and differential cross sections are obtained and investigated using the Monte-Carlo method of…
We define a minimal model with Universal Extra Dimensions, and begin to study its phenomenology. The collider signals of the first KK level are surprisingly similar to those of a supersymmetric model with a nearly degenerate superpartner…
Tests of lepton-universality as rate ratios in $b\to s \ell\ell$ transitions can be predicted very accurately in the Standard Model. The deficits with respect to expectations reported by the LHCb experiment in muon-to-electron ratios of the…
In the Standard Model the process $q\bar{q}\rightarrow q\bar{q}V$ (where $V=W^\pm,Z^0$ or $\gamma$) can occur via gluon exchange and also via $W^\pm$ or $Z^0$ exchange. The corresponding chromodynamic and electroweak amplitudes can…
Low-energy supersymmetry is a theoretical extension of the Standard Model of particle physics in which supersymmetry is invoked to explain the origin of the electroweak scale. In this approach, the energy scale of supersymmetry breaking can…
We consider a stabilized RS1 model in the energy range below the direct production of KK states. In this range we work out the effective Lagrangian due to exchange of heavy KK tensor graviton and scalar radion states and compute explicitly…
We compute the real and imaginary parts of the one-loop electroweak contributions to the left and right tensorial anomalous couplings of the $tbW$ vertex in the Standard Model (SM). For both tensorial couplings we find that the real part of…
High precision experimental new electroweak results measured at the four LEP experiments and the SLD collaboration are discussed. Heavy quark (b b-bar and c c-bar) forward-backward asymmetries measured at LEP are presented along with…
In this note we present an example of an extension of the Standard Model where unification of strong and electroweak interactions occurs at a level comparable to that occurring in the minimal supersymmetric standard model.
We propose a scheme in that the masses of the heavier leptons obey seesaw type relations. The light lepton masses, except the electron and the electron neutrino ones are generated by one loop level radiative corrections. We work in a…
Selected topics on precision tests of the Standard Model of the Electroweak and the Strong Interaction at the LEP $e^+e^-$ collider are presented, including an update of the world summary of measurements of $\alpha_s$, representing the…