Back to search

FRINATEK-Fri prosj.st. mat.,naturv.,tek

Study of Rare B Decays

Awarded: NOK 2.6 mill.

In the ATLAS experiment we want to perform the first study of the very rare B decay Bs -> mu+mu- using a multivariate analysis technique. The resullts provide another important test of the Standard Model. We will validate our analysis procedure on the exc lusive decays Bs->J/psi psi and B ->J/psi K(*), with J/psi -> mumu. Depending on the data quality we will also try to look at the electroweak penguin decays Bs-> phi mu+ mu- and B -> K* mu+ mu-. We plan to produce first results with a sample taken from m iddle of 2008 to winter 2009. Even if we do not see any signs of New Physics in any of these studies, the results, nevertheless, will impose new stringent constraints on the parameter space of models beyond the Standard Model (e.g. supersymmetry). In the BABAR experiment we plan to complete the studies that we have already started. This includes measurements of the q**2 dependence of the lepton forward-backward asymmetry, the longitudinal polarization, CP asymmetries and branching fractions in the exclus ive B -> K(*) l+l- decay modes and the inclusive B -> Xs l+ l- decay using multivariate analysis techniques. With the present BABAR data sample reaching an integrated luminosity of 477/fb, which corresponds to 660 million B meson pairs, we reach a reason able precision to perfom an important test of the Standard Model. Using a fit of the three-dimensional angular distribution we also plan to determine the decay amplitudes and phases. We will provide intermediate results on a sample of about 350/fb.

Funding scheme:

FRINATEK-Fri prosj.st. mat.,naturv.,tek