Establishment of Bs meson production at the psi(5S) energy using beauty and charm decays

The Upsilon(5S) resonance has long been thought to be a source of Bs mesons, since it is massive enough to produce BsBs pairs. In this work, we establish the presence of Bs mesons at the Upsilon(5S) energy and measure its production rate using both beauty and charm decays. We use all the e+e - collision data collected by the CLEO III detector at the Upsilon(5S) and at the Upsilon(4S) resonance energies. This data consists of 0.423 fb -1 on the Upsilon(5S) resonance, 6.34 fb-1 on the Upsilon(4S) and 2.32 fb-1 in the continuum below the Upsilon(4S). We also use 281 pb-1 data accumulated with the CLEO-c detector on the psi (3770) resonance and another 195 pb -1 taken in the region near 4170 MeV center-of-mass energy.; In the first analysis, we measure the asymmetry of Ds meson production in Upsilon(4S) and Upsilon(5S) decays as B (Upsilon(5S) → DsX)/ B (Upsilon(4S) → DsX) = (2:5 +/- 0.2+0.4-0.3 ). We take advantage of this asymmetry, which is due to the difference of B and Bs meson production in the decays of the two resonances, to establish Bs meson production in Upsilon(5S) decays and measure its fraction, f s, as (16:8+/- 2.6+6.7-3.4 )% using a theoretical estimate of (92+/-11)% for the inclusive branching ratio B (Bs → DsX). We also show the dependence of this measurement on the D+s → &phis;pi+ branching fraction.; Knowledge of the Bs production rate at the Upsilon(5S) resonance is imperative for Bs studies at the Upsilon(5S) using current B-factories, and for future e +e- Super-B Factories. We show in the second part of this work that the determination of fs in a model independent manner requires several tens of fb-1. We present a method that provides a measurement of fs using the relative rates of like-sign versus opposite sign dileptons; the like-sign leptons result from B 0 and Bs mixing. In addition, we show that determining the rates of single, double and triple D+/-s mesons provides an alternative way of finding fs.; To constrain our knowledge of Bs production at the Upsilon(5S) by making other measurements with other model dependencies, we examine CLEO-c data for other particle species than Ds, that are produced with much higher rate in Bs meson decays than in B meson decays. Such particle like eta, eta' and &phis;, with their ss quark composition, are expected to be enhanced in Ds than in D meson decays. We therefore measure the inclusive branching fractions of charm mesons, namely D0, D + and D+s , into etaX, eta'X, and &phis;X decays. We find that the rates from D+s are much larger than from D0 and D+.; We use the inclusive &phis; meson yields which is higher by one order of magnitude in Ds than in D decays to make a second measurement of B (Upsilon(5S) → B*sB*s ) using our model estimate of B (Bs → &phis;X). We measure B (Upsilon(5S) → &phis;X) = (13:8 +/- 0.7+2.3-1.5 )% and B (Upsilon(4S) → &phis;X) = (7:1 +/- 0:1 +/- 0:6)%, the ratio of the two rates is (1:9 +/- 0.1+0.3-0.2 ). This is the first measurement of the &phis; meson yield from the Upsilon(5S). We measure fs = (24:6+/- 2.9+11.0-5.3 )% and we also report on the total Upsilon(5S) hadronic cross section above continuum to be sigma(e+ e- Upsilon(5S)) = (0:301 +/- 0:002 +/- 0:039) nb. This allows us to extract the fraction of B mesons as (58:9 +/- 10:0 +/- 9:2)%, equal to 1- fs. Averaging the three methods gives a model dependent result of fs = ( 21+6-3 )%.