Related papers: Electroweak penguin decays at LHCb

Decays of $B$ mesons involving the transition of a $b$ quark into an $s$ quark are good probes of physics beyond the standard model. Such decays are studied at the Belle II experiment, a detector located along the SuperKEKB…

Rare lepton decays of the B(s), D and K mesons are sensitive probes of New Physics. In particular, the search for the decays $B^0_(s) -> \mu^+ \mu^-$ provides information on the presence of new (pseudo-)scalar particles. LHCb is well suited…

The present B -> pi K data is studied in the context of the standard model (SM) and with new physics (NP). We confirm that the SM has difficulties explaining the B -> pi K measurements. By adopting an effective-lagrangian parametrization of…

The 2.5 sigma discrepancy between theory and experiment observed in the difference Delta ACP = ACP(B- --> pi0 K-) - ACP(Bb0 --> pi+ K-) can be explained by a new electroweak (EW) penguin amplitude. Motivated by this result, we have analyzed…

Rare $B$, $D$ and $K$ decays provide interesting probes of the Standard Model (SM), with a potential sensitivity to New Physics (NP) higher than other, more common, decays. Their experimental measurement is challenging, and their…

New data from the BaBar, Belle, and CLEO Collaborations on B decays to two-body charmless final states are analyzed, with the following consequences: (1) The penguin amplitude which dominates the decay $B^+ \to \pi^+ K^{*0}$ has a magnitude…

We study the penguin pollution in the B^0 -> J/psi K_S decay up to leading power in 1/m_b and to next-to-leading order in \alpha_s, m_b being the b quark mass and \alpha_s the strong coupling constant. The deviation \Delta S_{J/psi K_S} of…

The penguin mediated processes $b\rightarrow s g$ and $b\rightarrow s l^+l^-$ are studied. In the Standard Model, for the leptonic modes improvement in experimental limits will put strigient bounds on the top mass, where the present limit…

Non-leptonic $B$ decays into charmless final states offer an important laboratory to study CP violation and the dynamics of strong interactions. Particularly interesting are $B^0_s\to K^-K^+$ and $B^0_d\to\pi^-\pi^+$ decays, which are…

We underline the theoretical and experimental interest of the vector-vector penguin decays ${\rm \overline{B}}_{d,s} \to {\rm K^{*0} \overline{K}^{*0}}$ for which the data show a strong U-spin violation. Indeed, with the latest LHCb data…

We study the effect of a sequential fourth generation on b\to s gamma, B_s mixing, B\to K^{(*)}\ell^+\ell^-, X_s\ell^+\ell^- and \phi K_S, taking into account the presence of a new CP phase in quark mixing. We find that the effects via…

We show that the anomalies in the $B\to\pi\pi$ decay channels, {\em viz.}, the large branching ratio of $B\to\pi^0\pi^0$ and large direct CP asymmetry of $B\to\pi^+\pi^-$, can both be explained, even in the framework of existing theoretical…

The penguin-dominated two-body weak decay of $\Lambda_b\rightarrow \Lambda \phi$ is studied based on the perturbative QCD approach. In addition to the penguin emission diagrams, the penguin exchange and $W$ exchange ones are also accounted…

The Standard-Model interpretation of the ratios of charged and neutral B-> pi K rates, R_c and R_n, respectively, points towards a puzzling picture. Since these observables are affected significantly by colour-allowed electroweak (EW)…

We formulate the most-general time-dependent decay distributions of $B_s\to J/\psi (\to l^+l^-) \phi(\to K^+K^-)$ in which the direct CP violation is explicitly incorporated. We then investigate the $B \to J/\psi V$ decays in the…

LHCb is the heavy flavour precision experiment of the proton-proton Large Hadron Collider (LHC) at CERN. It will search for new physics in CP violation and rare decays and is ready for the start-up of the LHC. An overview of its physics…

The measurements in $b\to s$ penguin-dominated decays are widely recognized as a powerful test for searching for New Physics by studying the deviation from theoretical estimations within the Standard Model. We examine the final-state…

The decays $B_d^0\rightarrow D_d^-D_d^+$ and $B_s^0\rightarrow D_s^-D_s^+$ probe the CP-violating mixing phases $\phi_d$ and $\phi_s$, respectively. The theoretical uncertainty of the corresponding determinations is limited by contributions…

We report on new results on $B \to K^* \gamma$ and recent studies on $B \to K^* \ell^+ \ell^-$ and $B \to h \nu \bar{\nu}$ at Belle at KEKB accelerator. All the analyses used full data sample of 711~fb${}^{-1}$ taken on $\Upsilon(4S)$…

Applying perturbative QCD methods recently seen to give a good description of the two body hadronic decays of the B meson, we address the question of bound-state effects on the decay B into K* + gamma. Consistent with most analyses, we…