Measurement of form-factor independent observables in the decay $B^{0} to K^{*0} mu^+ mu^-$

We present a measurement of form-factor independent angular observables in the decay mbox{$B^0to K^{*}(892)^{0}mu^+ mu^-$}. The analysis is based on a data sample corresponding to an integrated luminosity of 1.0fb$^{-1}$, collected by the LHCb experiment in $pp$ collisions at a center-of-mass energy of 7TeV. Four observables are measured in six bins of the dimuon invariant mass squared, $q^2$, in the range $0.1<q^2<19.0$GeV$^{2}$/c$^{4}$. Agreement with Standard Model predictions is found for 23 of the 24 measurements. A local discrepancy, corresponding to $3.7$ Gaussian standard deviations, is observed in one $q^2$ bin for one of the observables. Considering the 24 measurements as independent, the probability to observe such a discrepancy, or larger, in one is $0.5%$.

Search for new physics in $B_s rightarrow mu^+ mu^-$ and $B rightarrow K^{(*)} mu^+ mu^-$

Transitions of the type $b to s l^+ l^-$ are flavour changing neutral current processes where new physics can enter in competing loop diagrams with respect to the Standard Model contributions. In these decays several observables sensitive to new physics, and where theoretical uncertainties are under control, can be constructed. Particularly interesting are the angular asymmetries in the decay $B_d to K^* mu^+ mu^-$ and the measurement of the branching fraction of the decays $B_{s,d} to mu^+ mu^-$. Recent measurements of these observables and the measurement of the isospin asymmetry in the decays $B to K^{(*)} mu^+ mu^-$ are presented.

$B_sto mu^{+}mu^{-}$ the at LHC

The ATLAS, CMS and LHCb experiments will perform extensive searches for physics Beyond the Standard Model (BSM). The investigation of decays of beauty hadrons represents an alternative and complementary approach to the direct BSM searches. A particularly promising observable for the search of New Physics (NP) in $B-$hadron decays, is the measurement of the branching ratio of the decay $B_Sto mu^{+} mu^{-}$. This observable is sensitive to physics BSM with new scalar or pseudoscalar effective operators, such as theories involving an extended Higgs sector. Here the prospects of the ATLAS, CMS and the LHCb experiments for such a measurement are discussed. In particular the LHCb experiment, thanks to its good particle identification and momentum resolution, has the potential for an early discovery of this decay.