Marco Pappagallo (Universita & INFN, Bari)
We present a measurement of the absolute branching fraction Br(Ds->µ v_µ) and Br(Ds->τ v_τ) and of the Ds decay constant, f_Ds, using 521 fb-1} of data collected by the BABAR detector at the PEP-II storage rings at SLAC. We also obtained an upper limit on Br(Ds->e v_e). Ds events are detected by reconstructing the recoiling system, D K X γ, in events of the type e+e-->D K X Ds*, where Ds*->Ds γ and X represents additional pions from fragmentation. We also perform a Dalitz plot analysis of ~10^5 Ds+->K+ K- π+ decays. Events are selected from continuum e+e- annihilations using 384 fb-1 of data collected with the BaBar detector at PEP-II. A model-independent partial wave analysis is performed in the low K+K- mass region which allows to extract the S and P-wave amplitudes and their relative phase. We also measure relative branching fractions of Ds+->K+ K- K+ and Ds+->K+ K+ π-.
Michael Roney (SLAC)