Related papers: Model-independent analysis on $R(K^{(*)})$
A recent LHCb measurement of the ratio $R_{K^*}$ of $B\to K^*\mu\bar\mu$ to $B\to K^*e\bar e$ branching fractions has produced results in mild tension with the standard model (SM). This adds to the known anomalies also induced by the $b\to…
A global fit to the recent B->K*mu+mu- data shows indications for a large new-physics contribution to the Wilson coefficient of the semi-leptonic vector operator. In this article we consider a simple Z'-boson model of 3-3-1 type that can…
We present the results of a search for $B^{+}\to\gamma \ell^{+}\nu_{\ell}$, where $\ell = e, \mu$. We use a sample of 232 million $B\bar{B}$ pairs recorded at the $\Upsilon(4S)$ with the BaBar detector at the PEP-II $B$ Factory. We measure…
In the semileptonic decays of heavy mesons and baryons the lepton-mass dependence factors out in the quadratic $\cos^2\theta$ coefficient of the differential $\cos\theta$ distribution. We call the corresponding normalized coefficient the…
We present a search for the lepton-flavour-violating decays $B^+ \to K^+ \tau^\pm \ell^\mp$, with $\ell = (e, \mu)$, using the full data sample of $772 \times 10^6$ $B\overline{B}$ pairs recorded by the Belle detector at the KEKB…
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…
Depending on the assumptions on the power corrections to the exclusive b -> s l+ l- decays, the latest data of the LHCb collaboration - based on the 3 fb^-1 data set and on two different experimental analysis methods - still shows some…
We have investigated $B \to (K,K^*)(l\bar l,\nu\bar\nu)$ decay channels and predicted some form factor dependent observables (e.g. branching ratio, forward-backward asymmetry and lepton polarization asymmetry) considering new physics…
We determine the rates of the $B$ meson decays into a $K^{(*)}$ and an $\ell^+ \ell^-$ bound state, the leptonium, where $\ell = e,\mu,\tau$. The two spin states of the leptonium, the spin singlet and the spin triplet, couple to the axial…
We present an up-to-date complete model-independent global fit to $b\to s\ell^+\ell^-$ observables that confirms patterns of New Physics able to explain the data. We include the recent LHCb measurements of $R_K$, $R_{K_S}$, $R_{K^{*+}}$,…
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…
The LHCb has measured the ratios of $B\to K^\ast\mu^+\mu^-$ to $B\to K^\ast e^+ e^-$ branching fractions in two dilepton invariant mass squared bins, which deviate from the Standard Model predictions by approximately $2.5\sigma$. These new…
We study the differential Branching ratio and CP asymmetry for the exclusive decay B --> K^* l^+ l^- in the three Higgs doublet model with additional global O(2) symmetry in the Higgs sector. We analyse dilepton mass square q^2 dependency…
The general analysis of lepton polarization asymmetries in rare B -> K^* l^+ l^- decay is investigated. Using the most general, model independent effective Hamiltonian, the general expressions of the longitudinal, normal and transversal…
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…
A number of measurements in decays induced by the semileptonic $b\to s$ and $b\to c$ transitions hint towards a possible role of new physics in both sectors. Motivated by these anomalies, we investigate the lepton flavor violating $B\to…
Latest Lattice results on $D$ form factors evaluation from first principles show that the standard model (SM) branching ratios prediction for the leptonic $D_s \to \ell \nu_\ell$ decays and the semileptonic SM branching ratios of the $D^0$…
We have searched for neutrinoless $\tau$ lepton decays into $\ell$ and $V^0$, where $\ell$ stands for an electron or muon, and $V^0$ for a vector meson ($\phi$, $\omega$, $K^{*0}$ or $\bar{K}^{*0}$), using 543 fb$^{-1}$ of data collected…
We study the decays $B\to K^{(*)}\ell^+\ell^-$ and $B_s\to \ell^+\ell^- (\ell=e,\mu)$ in the minimal supersymmetric standard model with R-parity violation (RPV). From the recent measurements of their branching ratios, we have derived new…
The parity solution to the strong CP problem necessarily extends the Standard Model to include the SU$(2)_{\rm R}$ gauge sector and imposes restrictions on the structure of the Yukawa interactions. In this framework, one can consider an…