No Arabic abstract
We present measurements on penguin dominated B decays which are sensitive to new physics, such as CP-violation parameters and branching fractions in $b to s qbar{q}$ and $b to d qbar{q}$ gluonic and radiative decays using a large sample of $Bbar{B}$ pairs recorded at the $Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric energy $e^+e^-$ collider.
An overview of the measurements of b->sgamma, b->dgamma and b->sll penguin transitions at the B Factories is presented.
We report on recent results on radiative and electroweak penguin B decays at Belle at KEKB accelerator.
Penguin transitions play a key role in the search of New Physics hints in the heavy flavor sector. During the last decade CDF has been exploring this opportunity with a rich study of two--body charmless decays of neutral B mesons into charged final--state particles. After briefly introducing the aspects of this physics peculiar to the hadron collision environment, I report on two interesting results: the first polarization measurement of the B^0_s --> phi phi decay and the update of the B^0(_s) --> h^+h^- decays analysis.
Electro-weak penguin and leptonic decays provide an indirect probe for physics beyond the Standard Model and contribute to the determination of Standard Model parameters. Copious quantities of B mesons produced at the B-Factories permit precision measurements of the electro-weak penguin decays and searches for leptonic decays. We review the current experimental status of b -> s(d) gamma, B^0 -> D^{*0} gamma, b -> s l^+ l^- and finally B->tau nu decays at BaBar.
A measurement of the photon polarization in radiative penguin $B$ decays provides a test of the Standard Model and a probe for New Physics, that can lead to a deviation from the Standard Model prediction of left-handed photons in $bto s gamma$. We propose a new method to measure the photon polarization using the baryonic decay $B^- to Lambdabar{p} gamma$. The $P$-violating $Lambda$-hyperon decay allows a measurement of the $Lambda$ helicity to be performed, which can be uniquely related to the photon polarization in a model-independent way. The $B^- to Lambdabar{p} gamma$ decay was recently measured to have a large branching fraction providing a possibility to get meaningful results with the data already available at LHC and B-factory experiments. An increase of the $B$-meson sample at high luminosity LHC experiments and Belle II should provide a really stringent test by using this method already in the near future.