We have measured the charge asymmetry in like-sign dilepton yields from B(0)B*(0) meson decays using the CLEO detector at the Cornell Electron Storage Ring. We find a(0)(ll) identical ...withN(l(+)l(+))-N(l(-)l(-))/N(l(+)l(+))+N(l(-)l(-)) = +0.013+/-0.050+/-0.005. We combine this result with a previous, independent measurement and obtain Re(epsilon(B))/(1+ the absolute value of epsilon(B)(2)) = +0.0035+/-0.0103+/-0.0015 (uncertainties are statistical and systematic, respectively) for the CP impurity parameter, epsilon(B).
We have measured the CP asymmetry A(CP) identical withgamma(b-->sgamma)-gammab-->sgamma)/gamma(b-->sgamma)+gamma(b-->sgamma) to be A(CP) = (-0.079+/-0.108+/-0.022) (1.0+/-0.030), implying that, at ...90% confidence level, A(CP) lies between -0.27 and +0.10. These limits rule out some extreme non-standard-model predictions, but are consistent with most, as well as with the standard model.
Observation of B --> phiK and B --> phiK Briere, R A; Vogel, H; Gritsan, A ...
Physical review letters,
2001-Apr-23, 20010423, Letnik:
86, Številka:
17
Journal Article
Recenzirano
We have studied two-body charmless hadronic decays of B mesons into the final states straight phiK and phiK(*). Using 9.7 million B pairs collected with the CLEO II detector, we observe the decays B- ...--> phiK- and B0--> phiK(*0) with the following branching fractions: B(B--->phiK-) = (5.5(+2.1)(-1.8)+/-0.6)x10(-6) and B(B0--> phiK(*0)) = (11.5(+4.5+1.8)(-3.7-1.7))x10(-6). We also see evidence for the decays B0-->phiK0 and B---> phiK(*-). However, since the statistical significance is not overwhelming for these modes, we determine upper limits of <12.3x10(-6) and <22.5x10(-6) ( 90% confidence level), respectively.
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.
The CLEO experiment at the CESR collider has used 13.7 fb(-1) of data to search for the production of the Omega(0)(c) (css ground state) in e(+)e(-) collisions at square root of (s) approximately ...10.6 GeV. The modes used to study the Omega(0)(c) are Omega(-)pi(+), Omega(-)pi(+)pi(0), Xi-K-pi(+)pi(+), Xi0K-pi(+), and Omega(-)pi(+)pi(+)pi(-). We observe a signal of 40.4+/-9.0(stat) events at a mass of 2694.6+/-2.6(stat)+/-1.9(syst) MeV/c(2), for all modes combined.
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.
We report on a search for charmless hadronic B decays to the three-body final states, K0S h+ pi-, K+ h- pi0, K0S h+ pi0 (h+- denotes a charged pion or kaon), and their charge conjugates, using 13.5 ...fb^{-1} of integrated luminosity produced with center-of-mass energies near 10.6 GeV, and collected with the CLEO detector. We observe the decay B --> K0 pi+ pi- with a branching fraction (50 +10-9(stat.) +-7(syst.)) x 10^{-6} and the decay B --> K*+(892) pi- with a branching fraction (16 +6-5(stat.) +-2(syst.)) x 10^{-6}.
Korean adoptees placed by Associated Catholic Charities of Baltimore between January, 1985, and December, 1988 (N = 873), underwent surveillance for tuberculosis (TB). Overall tuberculin reactivity ...or active TB was documented in nine placements. Two children had active disease; both were skin test-negative and one died of tuberculous meningitis. The median age of the seven asymptomatic tuberculin reactors, none of whom had received Bacillus Calmette-Guérin vaccination, was 1 year. This reactivity rate is approximately 50 times greater than that of age-matched United States-born children. We conclude that high risk pediatric groups for TB, in addition to refugees, displaced persons and black and Hispanic minorities, include children involved in international adoption. Total reliance cannot be placed on screening tuberculin skin tests, and TB must be included in the differential diagnosis of high risk children presenting with recurrent pneumonia, fever of unknown origin, failure to thrive and altered mental status.
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