The absolute branching fractions for the decays Ds-→ℓ-ν̅ ℓ (ℓ=e, μ, or τ) 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 PEP-II e+e- collider at SLAC. The number of Ds- mesons is determined by reconstructing the recoiling system DKXγ in events of the type e+e-→DKXDs*-, where Ds*-→Ds-γ and X represents additional pions from fragmentation. The Ds-→ℓ-νℓ events are detected by full or partial reconstruction of the recoiling system DKXγℓ. The branching fraction measurements are combined to determine the Ds- decay constant fDs=(258.6±6.4±7.5) MeV, where the first uncertainty is statistical and the second is systematic
Measurement of the Absolute Branching Fractions for Ds−− and Extraction of the Decay Constant fDs.
PERUZZI, Ida Marena;BIASINI, Maurizio
2010
Abstract
The absolute branching fractions for the decays Ds-→ℓ-ν̅ ℓ (ℓ=e, μ, or τ) 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 PEP-II e+e- collider at SLAC. The number of Ds- mesons is determined by reconstructing the recoiling system DKXγ in events of the type e+e-→DKXDs*-, where Ds*-→Ds-γ and X represents additional pions from fragmentation. The Ds-→ℓ-νℓ events are detected by full or partial reconstruction of the recoiling system DKXγℓ. The branching fraction measurements are combined to determine the Ds- decay constant fDs=(258.6±6.4±7.5) MeV, where the first uncertainty is statistical and the second is systematicI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
