Download or read book Measurement of the D-s Decay Constant FDs and Observation of New Charm Resonances Decaying to D*[pi]. written by and published by . This book was released on 2012 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: The absolute branching fractions for the decays D-s 2!l-$\bar{v}$-(l = e, [mu], or [tau]) are measured using a data sample corresponding to an integrated luminosity of 521 fb-1 collected at center of mass energies near 10.58 GeV with the BABAR detector at the PEPII e+e- collider at SLAC. The number of Ds- mesons is determined by reconstructing the recoiling system DKX[gamma] in events of the type e+e- 2!DKXD*s-, where D*s- 2!Ds- [gamma] and X represents additional pions from fragmentation. The Ds- 2!l-vl events are detected by full or partial reconstruction of the recoiling system DKX[gamma]l. The following results are obtained: [beta](Ds- 2![mu]-v) = (6.02 ± 0.38 ± 0.34) x 10-3, [Beta](Ds-2![tau]-v) = (5.00 ± 0.35 ± 0.49) x 10-2, and B(Ds- 2!e-[nu])