相关论文: Penguin-like Diagrams from the Standard Model

We show that the dynamics responsible for the variation of the Yukawa couplings of the Standard Model fermions generically leads to a very strong first-order electroweak phase transition, assuming that the Yukawa couplings are large and of…

The $Z'$-gauge boson in an $U(1)_{L_\mu-L_\tau}$ gauge symmetry has two interesting features: one is its vector couplings to the charged leptons, and the other is the decoupling from the electron. Based on these properties, we investigate…

The updated analysis of the LHCb Collaboration on the lepton flavor violation suggests that the new physics should couple to muons and electrons with comparable magnitudes, resulting in the anomalies in both rare decay channels, $b…

Meson and anti-meson mixing processes constitute an important source of constraints on models that give tree level contributions to flavor violating neutral processes. In electroweak $ \text{SU}(3)_\text{L} \times \text{U}(1)_N $ models,…

Flavor physics, like cosmology, is likely in need of new basic ideas; the puzzles of elementary particle mass hierarchies and in particular the e-mu-tau and neutrino ones still remain mysteries. In this paper a new idea of dynamical…

We investigate the impact of incorporating vector-like leptons into the Standard Model, aiming to address longstanding puzzles related to the anomalous magnetic moments of the muon and electron while maintaining consistency with neutrino…

The problem of a calculation of parameters of the Standard Model is considered in the framework of the compensation approach. Conditions for a spontaneous generation of effective interactions of fundamental fields are shown to lead to sets…

I argue that the observed flavor structures of leptons and quarks might imply the existence of certain flavor symmetries. The latter should be a good starting point to build realistic models towards deeper understanding of the fermion mass…

We calculate the one-loop renormalization group equations of the neutrino mass matrix when the Standard Model particle content is extended with a massive gauge boson which has family-dependent couplings to the left-handed leptons. We show…

$U(1)^\prime$ extensions of the standard model with generation-dependent couplings to quarks and leptons are investigated as an explanation of anomalies in rare $B$-decays, with an emphasis on stability and predictivity up to the Planck…

We study the patterns of flavour violation in renormalisable extensions of the Standard Model (SM) that contain vector-like quarks (VLQs) in a single complex representation of either the SM gauge group $G_{SM}$ or $G_{SM}' = G_{SM} \times…

Constraints on angles of Unitarity triangle are reviewed, and in particular constraint on $\gamma$ from limit on $\Delta m_s$ is emphasized. Effects of penguin diagram on measurement of $\beta$ and $\alpha$ are then reviewed. New…

The Standard-Model interpretation of the ratios of charged and neutral B-> pi K rates, R_c and R_n, respectively, points towards a puzzling picture. Since these observables are affected significantly by colour-allowed electroweak (EW)…

Leptoquarks are ubiquitous in several extensions of the Standard Model and seem to be able to accommodate the universality-violation-driven $B$-meson-decay anomalies and the $(g-2)_\mu$ discrepancy interpreted as deviations from the…

We discuss about a possibility of large electro-weak penguin contribution in B -> K pi from recent experimental data. The several relations among the branching ratios which realize when the contributions from tree type and electro-weak…

We analyse for the first time the CP violating ratio $\varepsilon'/\varepsilon$ in $K\to \pi\pi$ decays in leptoquark (LQ) models. Assuming a mass gap to the electroweak (EW) scale, the main mechanism for LQs to contribute to…

The low-energy manifestations of a minimal extension of the electroweak standard model based on the quark-lepton symmetry $SU(4)_V \otimes SU(2)_L \otimes G_R$ of the Pati--Salam type are analyzed. Given this symmetry the third type of…

We make an attempt to clarify the role of the annihilation or "penguin" mode in the description of the $K\rightarrow\pi\pi$ decay within the Standard Model. The attention is concentrated on new operators in the effective $\Delta S=1$…

We study the influence of penguin (especially, electroweak penguin) effects on some methods of measuring the angles $\alpha$, $\beta$, and $\gamma$ in the CKM unitarity triangle. We use next-to-leading order effective Hamiltonian, and…

Physics beyond the standard model of electroweak interactions that violates lepton number will, in general, induce operators involving the quark and lepton fields that violate lepton number. I point out that some matrix elements of…