Abstract:

Over the last few years, the B factories at SLAC, USA, and KEK, Japan, have verified the Cabibbo-Kobayashi-Maskawa mechanism of CP violation in the Standard Model through the study of tree-dominated decays of the B meson. The focus of the B factories has now shifted to the search for signatures of new physics beyond the Standard Model, particularly through the study of flavor-changing neutral currents, which proceed through "penguin" diagrams involving a virtual loop. These decays are suppressed in the Standard Model, increasing sensitivity to new-physics effects but decreasing branching fractions. Exploiting large and growing datasets, BaBar and Belle have made many measurements in the penguin decays where a b quark transitions to an s quark, observing hints of possible deviations from Standard Model expectations in CP-violating measurements. In this talk, I describe the observation of and the first CP-asymmetry measurement in the corresponding gluonic b-to-d penguins, which are further suppressed in the Standard Model and have not been previously observed. The observation of the decays B->K0K0bar and B->K0barK+ opens a new sector of enquiry for the B factories. I will also describe the update to the BaBar muon detector using Limited Streamer Tube technology.