Related papers: A Global Likelihood for Precision Constraints and …
We present results from a global fit of Standard Model parameters and dimension-6 SMEFT Wilson coefficients that includes electroweak, Drell-Yan, Higgs-boson, top-quark, and flavour observables. Fits obtained by floating individual…
In the Standard Model and many of its extensions, it is well known that all of the observables associated with the rare decays $b\to s\gamma$ and $b\to s\ell^+\ell^-$ can be expressed in terms of the three Wilson coefficients,…
The seeming violation of universality in the tau lepton coupling to the W boson suggested by LEP II data is studied using an Effective Field Theory (EFT) approach. Within this framework we explore how this feature fits into the current…
The measurements carried out at LEP and SLC projected us into the precision era of electroweak physics. This has also been relevant in the theoretical interpretation of LHCb and Belle measurements of rare $B$ semileptonic decays, paving the…
We perform a model-independent analysis of $|\Delta b|=|\Delta d|=1$ processes to test the standard model and probe flavor patterns of new physics. Constraints on Wilson coefficients are obtained from global fits to $B^+ \to \pi^+…
We critically analyze the body of results that hints to the existence of New Physics from possible violations of lepton universality observed by the LHCb experiment in the $\mu/e$ ratios $R_{K}$ and $R_{K^*}$ to the $g-2$ lepton anomalies.…
The Standard Model Effective Field Theory (SMEFT) offers a systematic approach to study potential deviations from the Standard Model (SM) through higher-dimensional operators that encapsulate new physics effects. In this work, we analyze…
In view of both the latest LHCb measurement of $R_{K^{(*)}}$ and the new $2.8\sigma$ deviation reported by Belle II on $B^{+}\to K^{+}\nu\bar{\nu}$ decays, we present a fit to the $B$ meson anomalies for various one and two dimensional…
In the Standard Model (SM), the coupling of the electroweak gauge bosons to the leptons is lepton flavour universal. Tests of this property constitute sensitive probes for new physics models that violate lepton flavour universality. Recent…
We calculate the double pole contribution to two to four fermion scattering through $W^{\pm}$ currents at tree level in the Standard Model Effective Field Theory (SMEFT). We assume all fermions to be massless, $\rm U(3)^5$ flavour and $\rm…
The persisting anomalous data in semileptonic B-decays point towards New Physics models exhibiting large sources of Lepton Flavour Universality Violation. In this work we generalise previous studies by considering frameworks which include…
We present constraints on Wilson coefficients from a combined fit to data from top-quark and beauty-physics measurements within the Standard Model effective field theory. We consider present data on top-quark pair production and decay,…
The LHCb experiment has made several measurements in $b \to s$ transitions which indicate tensions with the Standard Model predictions. Assuming the source of these tensions to be new physics, we present new global fits to all Wilson…
The Standard Model of particle physics predicts that charged leptons have the same electroweak interaction strength. This symmetry, called lepton flavour universality, was found to hold in a wide range of particle decays. One observable…
In the absence of direct evidence of new physics, any ultraviolet theory can be reduced to its specific set of low-energy effective operators. As a case study, we derive the effective field theory for the seesaw extension of the Standard…
We compile information from low-energy observables sensitive to flavor-conserving 4-fermion operators with two or four leptons. Our analysis includes data from e+e- colliders, neutrino scattering on electron or nucleon targets, atomic…
Starting from the general effective hamiltonian relevant to the $b\to s$ transitions, we derive the expressions for the full angular distributions of the $B \to K^{(\ast )} \ell_1 \ell_2$ decay modes, as well as for ${\cal B}(B_s \to…
We present analytic results for electroweak precision observables (EWPO) at next-to-leading order (NLO) in dimension-six SMEFT, with no assumptions on the flavour structure of SMEFT Wilson coefficients. The results are given in five…
The ability of present and future experiments to test the Standard Model in the $B$ meson sector is described. We examine the loop effects of new interactions in flavor changing neutral current $B$ decays and in $Z\to b\bar b$,…
The persistent anomalies observed in $b \to s\,(\ell^+\ell^-,\,\nu\bar{\nu})$ transitions continue to provide strong motivation for exploring possible extensions of the Standard Model (SM). Motivated by these discrepancies, we present a…