Related papers: Probing the photon polarization in $B \to K^*\gamm…

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…

The $B^0 \to K^{*0} \overline{K}^{*0}$ and $B^0_s \to K^{*0} \overline{K}^{*0}$ decays are studied using proton-proton collision data corresponding to an integrated luminosity of 3fb$^{-1}$. An untagged and time-integrated amplitude…

The photon polarization in $D_{(s)} \to K_1 (\to K\pi\pi) \gamma$ decays can be extracted from an up-down asymmetry in the $K \pi \pi$ system, along the lines of the method known to $B \to K_1 (\to K\pi\pi) \gamma$ decays. Charm physics is…

We discuss the possibilities of assessing a non-zero $C_{7\gamma}^\prime$ from the direct and the indirect measurements of the photon polarization in the exclusive $b \to s\gamma^{(*)}$ decays. We focus on three methods and explore the…

An angular analysis of the $B_s^0 \rightarrow \phi e^+e^-$ decay is performed using the proton-proton collision dataset collected between 2011 and 2018 by the LHCb experiment, corresponding to an integrated luminosity of $9\,{\rm fb}^{-1}$…

In this work we will study the longitudinal polarisations of both leptons in the decay process ${\bar B} \to {\bar K}_2(1430)\, \ell^+ \, \ell^-$. This process has all the features of the related and well investigated process ${\bar B} \to…

We discuss, in detail, the K* polarization states in the exclusive B meson decay B0-> K*0(-> K-pi+)l^+l^- (l=e, \mu, \tau) in the low dilepton mass region. We focus on the study of the angular distribution of this decay that provides…

We systematically compute and discuss meson and muon polarized radiative decays. Doubly differential distributions in terms of momenta and helicities of the final lepton and photon are explicitly computed. The undergoing dynamics giving…

Using the most general model independent form of the effective Hamiltonian, the rare B_s --> \gamma \ell^+ \ell^- decays are studied by taking into account the polarization of the photon. The total and the differential branching ratios for…

A time- and flavour-integrated amplitude analysis of $B^0$ and $B^0_s$ decays to the $(K^+\pi^-)(K^-\pi^+)$ final state in the $K^*(892)^0 \kern 0.18em \overline{\kern -0.18em K}{}^{*}(892)^0$ region is presented, using $pp$ collision data…

We present a general analysis of the lepton polarizations in the rare Bs ->\gamma \ell^+ \ell^- decays by using the most general model independent form of the effective Hamiltonian. The sensitivity of the longitudinal, transverse and normal…

We propose two novel methods for testing the standard model using external photon conversion at a high-luminosity e^+e^- B factory proposed recently. The first method is to measure the mixing-induced CP-violation parameter S_{pi^0pi^0} in…

We report the first measurement of the $\tau$ lepton polarization in the decay ${\bar B} \rightarrow D^* \tau^- {\bar\nu_{\tau}}$ as well as a new measurement of the ratio of the branching fractions $R(D^{*}) = \mathcal{B}({\bar B}…

The decays $K_{L,S} \to 3 \gamma $ are not forbidden by any selection rules or symmetry principles. However, gauge invariance and Bose statistics dictate that every photon pair in these transitions has at least two units of angular…

The standard model prediction for the $B\to X_{s,d}\gamma$ decay amplitude with a right-handed photon is believed to be tiny, suppressed by $m_{s,d}/m_b$, compared to the amplitude with a left-handed photon. We show that this suppression is…

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 first search for the $B_s^0\rightarrow K^-\pi^+\gamma$ decay in the range $796<m(K^-\pi^+)<1800\,\text{MeV/}c^2$ is performed using data from proton-proton collisions collected by the LHCb experiment at centre-of-mass energies of 7, 8,…

The transition amplitude of a kaon to a pion and two off-shell photons is studied. First, it is computed at leading order (one-loop level) of the Chiral Perturbation Theory expansion. Explicit analytical results for the leading-order…

A model-independent analysis for the exclusive, rare B -> K^* l^+ l^- decay is presented. Systematically studied are the experimentally measured quantities, such as, branching ratio, forward-backward asymmetry, longitudinal polarization of…

Multiple polarization observables must be measured to access the amplitude structure of pseudoscalar meson photoproduction off the proton. The hyperon-producing reactions are especially attractive to study, since the weak decays allow…