Related papers: Z penguins and rare B decays
The anomalously large like-sign dimuon charge asymmetry in semileptonic b-hadron decays recently measured by the D0 Collaboration may be hinting at the presence of CP-violating new physics in the mixing of B_s mesons. It has been suggested…
Recent theoretical results of the standard model expectations on $\sin2\beta_{\rm eff}$ from penguin-dominated $b \to s$ decays are briefly reviewed.
I review the recent progress on the perturbative QCD approach to exclusive $B$ meson decays, discussing the comparison of collinear and $k_T$ factorizations, the CP asymmetry in the $B^0\to\pi^+\pi^-$ decay, penguin enhancement, the…
In the absence of the QCD penguin contributions a measurement of the time-dependent asymmetry in the decay $B^0(t)\to \pi^+\pi^-$ gives directly the weak angle $\alpha$. Several bounds have been proposed in the literature on the magnitude…
Disentangling New Physics effects from the Standard Model requires a good understanding of all pieces that stem from the latter, especially the uncertainties that might plague the theoretical estimations within the Standard Model. In the…
We investigate rare semileptonic $B \to K^\ast\ell^+\ell^-$ by looking at the long distance contributions. Our analysis is limited to the very small values of physical accessible range of invariant mass of the leptonic couple $q^2$. We show…
The availability of data on $B_s$ decays to strange quasi-two-body final states, either with or without charmonium opens new possibilities for understanding different contributions of weak diagrams and in particular the relative…
This talk contains a short overview of the history of the interplay of the weak and the strong interaction and CP-violation. It describes the phenomenology and the basic physics mechanisms involved in the Standard Model calculations of…
We report recent results in rare B decays. Our focus will be on b -> d gamma and b -> s l^+ l^- transitions. We discuss their impact on the CKM phenomenology and their role within our search for new physics. In particular, we analyse the…
In this paper, we reexamine the new physics contributions to seven well measured $B \to PP$ decays in the standard model (SM) and the general two-Higgs-doublet model (model III) and compare the theoretical predictions with the new data.…
We examine new-physics (NP) effects in B decays with large b -> s penguin amplitudes. Decays involving b -> d penguins are assumed to be unaffected. We consider a model-independent parametrization of such NP. We argue that NP strong phases…
Isospin structure of gluon mediated or strong penguin is significantly altered when the full electroweak corrections are included. This has the consequence that some previous analyses which relied on a simple isospin structure in charmless…
We study the rare decays of $B_{s} \to M_s\ell \bar{\ell}$ ($M_s=\eta, \eta',\phi$ and $\ell=\nu,e,\mu,\tau$) in the standard model. With the hadronic form factors evaluated in the light front and constituent quark models, we estimate the…
A systematic experimental search for two-body hadronic decays of the b-quark of the type b to quark + meson is proposed. These reactions have a well defined experimental signature and they should be theoretically cleaner compared to…
Some discrepancies between theory and experiment in the B -> pi K decays suggest the possibility of a new physics contribution with the structure of an electroweak penguin amplitude. If such a scenario is realised in nature, the branching…
A review of the experimental status of purely leptonic ${B^0_{[s]}\to\ell^+\ell^-}$ decays is given and the new analysis of ${B^0_{[s]}\to\mu^+\mu^-}$ observables with the LHCb experiment is presented. The new results are the most precise…
We study the branching fractions and the lepton polarization asymmetries of rare $B \to X_s \tau^+ \tau^-$ and $B \to K^{(*)} \tau^+ \tau^-$ modes within the Standard Model and in the Appelquist-Cheng-Dobrescu model, which is a New Physics…
I discuss some puzzles observed in exclusive $B$ meson decays, concentrating on the large difference between the direct CP asymmetries in the $B^0\to \pi^\mp K^\pm$ and $B^\pm\to \pi^0 K^\pm$ modes, the large $B^0\to\pi^0\pi^0$ branching…
The general analysis of the rare Bc->D^*_s l^+ l^- decay is presented by using the most general, model independent effective Hamiltonian. The dependencies of the branching ratios, longitudinal, normal and transversal polarization…
We investigate the effect of an extra fourth quark generation and FCNC mediated $Z$ and $Z'$ bosons on the rare decay mode $B^- \to \phi \pi^-$. In the standard model, this mode receives only $b \to d$ penguin contributions and therefore,…