Related papers: $R(K^{(*)})$ with vector unparticles
Data in $B$-meson decays indicate violations of lepton flavour universality, thereby raising the question about such phenomena in the charm sector. We perform a model-independent analysis of NP contributions in (semi)-leptonic decays of…
We show how any flavour conserving $Z'$ model can be made flavour violating and non-universal by introducing mass mixing of quarks and leptons with a fourth family of vector-like fermions with non-universal $Z'$ couplings. After developing…
We study the recently found anomalies in $B$-meson decays within a scenario with a warped extra dimension where the Standard Model fermions are propagating in the bulk. The anomalies are then interpreted as the result of the exchange of…
We present a model-independent analysis of rare B decays, $B \to K^{(*)} \nu \nu$. The effect of possible new physics is written in terms of dimension-6 four-fermi interactions. The lepton number violating scalar- and tensor-type…
We investigate the consequences of deviations from the Standard Model observed in $b\to s\mu\mu$ transitions for flavour-changing neutral-current processes involving down-type quarks and neutrinos, under generic assumptions concerning the…
Current experimental information on the charm meson decay observables in which the $c\to s\ell\nu_\ell$ transitions occur is well compatible with the Standard Model predictions. Recent precise lattice calculations of the $D_s$ meson decay…
The latest measurements of rare $b\to s$ decays in the LHCb experiment have led to results in tension with the predictions of the standard model (SM), including a tentative indication of the violation of lepton flavor universality. Assuming…
We predict the branching ratios of the lepton flavor violating Z boson decays Z\to e^{\pm} \mu^{\pm}, Z\to e^{\pm} \tau^{\pm} and Z\to \mu^{\pm} \tau^{\pm} in the case that the lepton flavor violation is carried by the scalar unparticle…
We present measurements of the branching fractions for the decays $B\to K \mu^{+}\mu^{-}$ and $B\to K e^{+}e^{-}$, and their ratio ($R_{K}$), using a data sample of 711 $fb^{-1}$ that contains $772 \times 10^{6}$ $B\bar{B}$ events. The data…
B-anomalies hint towards New Physics violating Lepton Flavor Universality at the TeV scale. The way they manifest points out to very particular structures for this New Physics. In this talk I review some UV-complete models to explain the…
We predict the branching ratios of the lepton flavor violating radion decays r -> e^{\pm} \mu^{\pm}, r -> e^{\pm} \tau^{\pm} and r ->\mu^{\pm} \tau^{\pm} in the framework of the Randall-Sundrum scenario that the lepton flavor violation is…
Vector leptoquarks can address the lepton flavor universality anomalies in decays associated with the $b \to c \ell \nu$ and $b \to s \ell \ell$ transitions, as observed in recent years. Generically, these leptoquarks yield new sources of…
In the present work we study the effects of an unparticle $\unpart$ as the possible source of missing energy in the decay $B \to K (K^*) + {\rm missing energy}$. We find that the dependence of the differential branching ratio on the…
The most statistically significant hints for new physics in the flavor sector are discrepancies between theory and experiment in $B$ decays to lepton pairs ($b\to s\ell^+\ell^-$) and a deficit in $1^{\rm st}$ row CKM unitarity (the Cabibbo…
The measurements of several lepton flavor universality (LFU) violating observables in the decays induced by the quark level transition $b \to c \tau \bar{\nu}$ provide an inkling of plausible physics beyond the standard model of electroweak…
Semi-leptonic $B_s \to K \ell \nu$ and $B_s \to D_s \ell \nu$ decays provide an alternative $b$-decay channel to determine the CKM matrix elements $|V_{ub}|$ and $|V_{cb}|$ or to obtain $R$-ratios to investigate lepton flavor universality…
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…
In this work we study the potential of the lepton flavor ratios $R_{K}^{\tau \mu} \equiv \Gamma(B \to K \tau^+ \tau^-)/ \Gamma(B \to K \mu^+ \mu^-)$ and $ R_{K^{*}}^{\tau \mu} \equiv \Gamma(B \to K^* \tau^+ \tau^-)/ \Gamma(B \to K^* \mu^+…
In recent years, significant experimental indications that point towards Lepton Flavour Universality violating effects in B-decays, involving $b \to c \tau \nu$ and $b \to s \ell^+ \ell^-$ have been accumulated. A possible New Physics…
Several experiments observed deviations from the Standard Model (SM) in the flavour sector: LHCb found a $4-5\,\sigma$ discrepancy compared to the SM in $b\to s\mu^+\mu^-$ transitions (recently supported by an Belle analysis) and CMS…