相关论文: $\varepsilon'/\varepsilon$ in 331 Models
We perform a combined analysis of $B \to \pi \pi$ and $B \to \pi K$ decays with the current experimental data. Assuming SU(3) flavor symmetry and no new physics contributions to the topological amplitudes, we demonstrate that the…
This decade should provide the first definitive signals of New Physics (NP) beyond the Standard Model (SM) and the goal of these lectures is a review of flavour physics in various extensions of the SM that have been popular in the last ten…
In the context of the 331 models, we consider constraints on the extra neutral boson $Z^{\prime}$ predicted by the model, where three different quark family assignments are identified. Using the ansatz of Matsuda as an specific texture for…
The flavor-changing neutral current semileptonic decays of $B$ mesons provide an excellent platform for indirectly probing New Physics (NP) beyond the Standard Model (SM). Recent measurements of lepton flavor universality (LFU) ratios such…
We study the flavor physics in two extensions of the quark sector of the Standard Model (SM): a four generation model and a model with a single vector--like down--type quark (VDQ). In our analysis we take into account the experimental…
We explore CP-violating (CPV) effects of heavy New Physics in flavour-changing quark dipole transitions, within the framework of Standard Model Effective Field Theory (SMEFT). First, we establish the relevant dimension six operators and…
Following the recent analysis done in collaboration with Jason Aebischer and Christoph Bobeth, I summarize the optimal, in our view, strategy for the present evaluation of the ratio $\varepsilon'/\varepsilon$ in the Standard Model (SM). In…
We study extensions of the Standard Model where the charged current weak interactions are governed by the CKM matrix and where all tree-level decays are dominated by their Standard Model contribution. We constrain both analytically and…
The electroweak theory contains too many empirical parameters. Most of them are related to the flavor part of particle physics. In this paper we discuss a relevant simple idea: the complicated system of actual dimensionless, small versus…
The b -> ssdbar and b -> ddsbar decays are highly suppressed in the SM, and are thus good probes of new physics (NP) effects. We discuss in detail the structure of the relevant SM effective Hamiltonian pointing out the presence of nonlocal…
Recent improvements to the limit of Delta M_{B_s} imply that pure superweak theories, while not excluded, no longer provide a good fit to the data. A class of general superweak theories is introduced in which all flavor changing…
$Z^\prime$ models belong to the ones that can most easily explain the anomalies in $b\to s \mu^+\mu^-$ transitions. However, such an explanation by a single $Z^\prime$ gauge boson, as done in the literature, is severly constrained by the…
We present an analysis of the rare exclusive $B$ decays $B\to K\nu\bar\nu$ and $B\to K^{*}\nu\bar\nu$ within the Standard Model (SM), in a model-independent manner, and in a number of new physics (NP) models. Combining new form factor…
We present a particular warped extra dimensional model, where the flavour diagonal and flavour non-diagonal Z boson couplings to left-handed down quarks are protected by the custodial symmetry P_LR. After a brief introduction of the model…
We discuss direct $CP$ violation in the standard model by giving a new estimate of $\varepsilon'/\varepsilon$ in kaon decays. Our analysis is based on the evaluation of the hadronic matrix elements of the \mbox{$\Delta S =1$} effective…
Recent anomalies in decays induced by $b\to c \ell^- \bar\nu_\ell$ transitions raise the question about such phenomena in the $D$ decays induced by $c\to (s,d)\ell^+\nu_\ell$ transitions. In the experimental side, current measurements on…
In these proceedings I present a personal perspective of the challenges for new physics (NP) searches in the flavour sector. Since the CKM mechanism of flavour violation has been established to a very high precision, we know that physics…
The recent deviations of the experimental data on some parameters of the tree-level semileptonic $B$ and $B_c$ mesons decays from the standard model (SM) predictions indicate considerable violations of the lepton flavor universality, and as…
In the framework of the Standard Model Effective Field Theory, we compare the lower bounds on the scale of new physics possibly contributing to the $f\bar{f}h$ effective couplings, obtained from the measurements of different observables,…
Within $Z^\prime$ models, neutral meson mixing severely constrains beyond the Standard Model (SM) effects in flavour changing neutral current (FCNC) processes. However, in certain regions of the $Z^\prime$ parameter space, the contributions…