Within the standard model, we calculate the radiative B −→ K⋆γ decay rate based on a Bethe-Salpeter description for the meson wave functions and the hadronic matrix elements. With a reasonable choice of parameters the branching ratio BR(B −→ K⋆γ) is found to be (3.8 − 4.6) × 10−5, which is in agreement with the CLEO experimental data. We also find with mb = 5.12 GeV the ratio R ≡ Γ(B −→ K⋆γ)/Γ(...

We study the time evolution and decay of the neutral B-meson system using quantum dynamical semigroups. New, nonstandard terms appear in the expression of relevant observables; they can be parametrized in terms of six phenomenological constants. Although very small, these parameters may be detected in the new generation of dedicated B-meson experiments.

Using a data sample of 62 million Υ (4S) → BB decays collected between 1999 and 2001 by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC we study events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the flavour of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmet...

We present model independent constraints on the masses and couplings to fermions of B and L conserving leptoquarks. Such vector or scalar particles could have masses below 100 GeV and be produced at HERA; we list the generation dependent bounds that can be calculated from rare lepton and meson decays, meson-anti-meson mixing and various electroweak tests.