The authors measure the absolute branching fraction for D° → K−? using partial reconstruction of {bar B}° → D*+Xl−{bar {nu}}{sub {ell}} decays, in which only the charged lepton and the pion from the decay D*+ → D°?+ are used. Based on a data sample of 230 million B{bar B} pairs collected at the?(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC, they obtain?(D° → K−?+) = (4.007 ± 0.037 ± 0.070)%, where the first error is statistical and the second error is systematic.

The authors measure the absolute branching fraction for D{sup 0} {yields} K{sup -} {pi}{sup +} using partial reconstruction of {bar B}{sup 0} {yields} D*{sup +} X {ell}{sup -} {bar {nu}}{sub {ell}} decays. Only the charged lepton and the soft pion from the decay D*{sup +} {yields} D{sup 0} {pi}{sup +} are used. Based on a data sample of 230 million B{bar B} pairs collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC, they obtain {Beta}(D{sup 0} {yields} K{sup -} {pi}{sup +}) = (4.025 {+-} 0.038 {+-} 0.098)%, where the first error is statistical and the second error is systematic.

We present branching fraction measurements of charged and neutral B decays to D{pi}{sup -}, D*{pi}{sup -} and D**{pi}{sup -} with a missing mass method, based on a sample of 231 million {Upsilon}(4S) {yields} B{bar B} pairs collected by the BABAR detector at the PEP-II e{sup +}e{sup -} collider. One of the B mesons is fully reconstructed and the other one decays to a reconstructed charged {pi} and a companion charmed meson identified by its recoil mass, inferred by kinematics. Here D** refers to the sum of all the non-strange charm meson states with masses in the range 2.2-2.8 GeV/c{sup 2}.

The authors present a measurement of R{sub B}, the ratio of the branching fraction for the rare decay D° → K?− to that for the Cabibbo-favored decay D° → K−?+. Charge conjugate decays are implicitly included. A signal of 2005 ± 104 events for the decay D° → K+?− is obtained using the CDF II detector at the Fermilab Tevatron collider. The data set corresponds to an integrated luminosity of 0.35 fb−1 produced in {bar p}p collisions at √s = 1.96 TeV. Assuming no mixing, they find R{sub B} = [4.05 ± 0.21(stat) ± 0.11(syst)] x 10−3. This measurement is consistent with the world average, and comparable in accuracy with the best measurements from other experiments.

The authors present measurements of the branching fractions for the charmless two-body decays B° →??− and B° → K+?−, and a search for the decay B° → K+K−. They include the effects of final-state radiation from the daughter mesons for the first time, and quote branching fractions for the inclusive processes B° → h+h'−n?, where h and h' are pion or kaons. The maximum value of the sum of the energies of the n undetected photons, E{sub {gamma}}{sup max}, is mode-dependent. Using a data sample of approximately 227 million?(4S) → B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy e+e− collider at SLAC.