First observation of the decays B(0) --> D(*-)p_p pi+ and B(0) --> D(*-)p_n.
Phys Rev Lett 86:13 (2001) 2732-2736
Abstract:
We report the first observation of exclusive decays of the type B-->D(*)N_NX, where N is a nucleon. Using a sample of 9.7x10(6)B_B pairs collected with the CLEO detector operating at the Cornell Electron Storage Ring, we measure the branching fractions B(B0-->D(*-)p_p pi(+)) = (6.5(+1.3)(-1.2)+/-1.0)x10(-4) and B(B0-->D(*-)p_n) = (14.5(+3.4)(-3.0)+/-2.7)x10(-4). Antineutrons are identified by their annihilation in the CsI electromagnetic calorimeter.First observation of the decays B0 → D*- p̄π+ and B0 → D*-pn̄
Physical Review Letters 86:13 (2001) 2732-2736
Abstract:
Decay modes of the B0 of the type B → DNN̄X were observed. Measurements imply that DNN̄X final states may contribute substantially to the total observed B → barvon rate. Branching fractions were accurately measured.Measurement of the relative branching fraction of upsilon(4S) to charged and neutral B-meson pairs.
Phys Rev Lett 86:13 (2001) 2737-2741
Abstract:
We analyze 9.7x10(6) B_B pairs recorded with the CLEO detector to determine the production ratio of charged to neutral B-meson pairs produced at the Upsilon(4S) resonance. We measure the rates for B0-->J/psiK((*)0) and B+-->J/psiK((*)+) decays and use the world-average B-meson lifetime ratio to extract the relative widths f(+-) / f(00) = gamma(Upsilon(4S)-->B+B-) / gamma(Upsilon(4S)-->B0 B-0)) = 1.04+/-0.07(stat)+/-0.04(syst). With the assumption that f(+-)+f(00) = 1, we obtain f(00) = 0.49+/-0.02(stat)+/-0.01(syst) and f(+-) = 0.51+/-0.02(stat)+/-0.01(syst). This production ratio and its uncertainty apply to all exclusive B-meson branching fractions measured at the Upsilon(4S) resonance.Measurement of the lambda(+)(c) lifetime.
Phys Rev Lett 86:11 (2001) 2232-2236
Abstract:
The Lambda+c lifetime is measured using 9.0 fb(-1) of e+e- annihilation data collected on or just below the Upsilon(4S) resonance with the CLEO II.V detector at CESR. Using an unbinned maximum likelihood fit, the Lambda+c lifetime is measured to be 179.6+/-6.9(stat)+/-4.4(syst) fs. The precision of this colliding beam measurement is comparable to other measurements, which are based on fixed-target experiments, with different systematic uncertainties.Measurement of the Λc + lifetime
Physical Review Letters 86:11 (2001) 2232-2236