Related papers: Explaining the $R_K$ and $R_{K^*}$ anomalies
In this work we extend the SM by introducing only exotic scalars and leptons and show that within the reasonable error limits, both the observed anomalies in $R(D^{(*)})$ and $R_{K^{(*)}}$ can be explained along with satisfying all the…
We attempt to explain recent anomalies in semileptonic $B$ decays at LHCb via a composite Higgs model, in which both the Higgs and an $SU(2)_L$-triplet leptoquark arise as pseudo-Goldstone bosons of the strong dynamics. Fermion masses are…
The measurement of $R_D$ ($R_{D^*}$), the ratio of the branching fraction of $\overline{B} \to D \tau \bar{\nu}_\tau (\overline{B} \to D^* \tau \bar{\nu}_\tau)$ to that of $\overline{B} \to D l \bar{\nu}_l (\overline{B} \to D^* l…
It was previously shown that unlike the ratios $R_K^{\mu e} \equiv R_K \equiv \Gamma(B \to K \mu^+ \mu^-)/\Gamma(B \to K e^+ e^-)$ and $R_{K^*}^{\mu e} \equiv R_{K^*} \equiv \Gamma(B \to K^* \mu^+ \mu^-)/\Gamma(B \to K^* e^+ e^-)$, the…
More than $3\sigma$ deviations from the standard model are observed in the angular observable $P'_5$ of $B\to K^* \mu^+ \mu^-$ and muon $g-2$. To resolve these anomalies, we extend the standard model by adding two leptoquarks. It is found…
We report a measurement of the branching fraction of the exclusive charmless semileptonic decay B+ --> omega l+ nu, where l is either an electron or a muon. We use samples of B+ mesons tagged by a reconstructed charmed semileptonic decay of…
We present a precise calculation of the dilepton invariant-mass spectrum and the decay rate for $B^\pm \to \pi^\pm \ell^+ \ell^-$ ($\ell^\pm = e^\pm, \mu^\pm $) in the Standard Model (SM) based on the effective Hamiltonian approach for the…
We discuss the anatomy of the $L_{VV}$ observable designed as a ratio of the longitudinal components of $B_s \to VV$ versus $B_d \to VV$ decays. We focus on the particular case of $B_{d,s} \to K^{*0} {\bar K^{*0}}$ where we find for the SM…
There are several anomalous measurements in the decays induced by the quark level transition $b \to s \mu^+ \mu^-$, which do not agree with the predictions of the Standard Model. These measurements could be considered as signatures of…
The invariant mass spectrum of the lepton pair in inclusive semileptonic $\bar B\to X_u \ell\bar\nu$ decay yields a model independent determination of $|V_{ub}|$. Unlike the lepton energy and hadronic invariant mass spectra, nonperturbative…
We report preliminary measurements of the charmless exclusive semileptonic branching fractions of the B0 --> pi- l+ nu and B+ --> pi0 l+ nu decays, based on 211 fb-1 of data collected at the Y(4S) resonance by the BABAR detector. In events…
The ratio of branching fractions of the decays $\Lambda^{0}_{b}\to pK^{-}e^{+}e^{-}$ and $\Lambda^{0}_{b}\to pK^{-}\mu^{+}\mu^{-}$, $R^{-1}_{pK}$, is measured for the first time using proton-proton collision data corresponding to an…
There are some slight tensions with the SM predictions within the latest LHCb measurements. Besides the known anomaly in one angular observable of the rare decay B -> K* mu+ mu-, another small discrepancy recently occurred. The ratio R_K =…
We model-independently analyze the angular distributions of B -> K ll decays, l = e, mu, for low dilepton mass using QCD factorization. Besides the decay rate, we study the forward-backward asymmetry A_FB^l and a further observable, F_H^l,…
The study of the rare decays $B\to K^{(*)} \nu \bar\nu$ offers a window into the dynamics operating at the electroweak scale, allowing studies of the Standard Model and searches for heavy new physics. However, the analysis of these decays…
New heavy vector bosons and light scalars are predicted in a plethora of models of new physics. In particular, in new strongly interacting sectors they play the role of the $\rho$ and $\pi$ mesons in QCD. We show that some of their…
We analyze the new physics effects in semileptonic $\bar{B_s} \to K^{*+}(\to K\pi) \ell^- \bar{\nu}_\ell$ decay induced by the $b \to u \ell \nu_{\ell}$ quark level transition. We consider the vector, scalar and tensor new physics Lorentz…
Decays of $B$ mesons with leptons in the final state offer an interesting laboratory to search for possible effects of physics from beyond the Standard Model. In view of puzzling patterns in experimental data, the violation of lepton…
We study the single and double lepton polarization asymmetries in the semileptonic $B$ meson decays $B \to K_1 (1270) \ell^+ \ell^-$ $\ell \equiv e$, $\mu$, $\tau$), where the strange $P$-wave meson, $K_1(1270)$, is the mixtures of the…
This paper considers the implications of the heavy quark and chiral symmetries for the semi-leptonic decay $B \rightarrow D^* X \ell \bar \nu_\ell$. The general kinematic analysis for decays of the form {\sl pseudoscalar meson $\rightarrow$…