Bonn 2001 – wissenschaftliches Programm
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T: Teilchenphysik
T 608: Seltene Zerf
älle 2
T 608.3: Vortrag
Donnerstag, 29. März 2001, 10:30–10:45, HS XIII
Weak annihilation in the rare radiative B→ ργ decay — •Dmitri Melikhov1, Michael Beyer2, and Nikolai Nikitin3 — 1Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16, D-69120 Heidelberg — 2Fachbereich Physik, Universität Rostock, Universitätsplatz, 3, D-18051 Rostock — 3Institute of Nuclear Physics, Moscow State University, 119899, Moscow, Russia
We calculate the amplitude of the rare radiative FCNC B→ργ decay. The main penguin contribution to the amplitude is described by a single form factor that has been calculated previously. Here we focus on the weak-annihilation contribution generated by the 4-quark operator in the effective Hamiltonian. Assuming factorization, we analyze the general structure of the weak annihilation amplitude and obtain the parity conserving and parity violating parts in terms of the specific B and ρ form factors and leptonic decay constants. Within the relativistic dispersion approach based on the constituent quark picture we provide numerical estimates for the form factors of interest. We calculate both of the two contributions from photon emission: that by the quarks of the B-meson which gives the main effect and that of the ρ-meson which provides only a minor correction and has been neglected in previous analyzes.
Supported by Alexander-von-Humboldt Stiftung, Deutsche Forschungsgemeinschaft, Deutscher Akademischer Austauschdienst, and Land Mecklenburg-Vorpommern.