We measure the primary lepton momentum spectrum in $\overline{B}\ensuremath{\rightarrow}X\mathcal{l}\overline{\ensuremath{\nu}}$ decays, for ${p}_{\mathcal{l}}>~1.5\mathrm{GeV}/c$ in the B rest frame. From this, we calculate various moments of the spectrum. In particular, we find ${R}_{0}\ensuremath{\equiv}{\ensuremath{\int}}_{1.7\mathrm{GeV}}(d\ensuremath{\Gamma}{/dE}_{\mathrm{sl}}{)dE}_{\mathcal{l}}/{\ensuremath{\int}}_{1.5\mathrm{GeV}}(d\ensuremath{\Gamma}{/dE}_{\mathrm{sl}}{)dE}_{\mathcal{l}}=0.6187\ifmmode\pm\else\textpm\fi{}{0.0014}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.0016}_{\mathrm{sys}}$ and ${R}_{1}\ensuremath{\equiv}{\ensuremath{\int}}_{1.5\mathrm{GeV}}{E}_{\mathcal{l}}(d\ensuremath{\Gamma}{/dE}_{\mathrm{sl}}{)dE}_{\mathcal{l}}/{\ensuremath{\int}}_{1.5\mathrm{GeV}}(d\ensuremath{\Gamma}{/dE}_{\mathrm{sl}}{)dE}_{\mathcal{l}}=(1.7810\ifmmode\pm\else\textpm\fi{}{0.0007}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.0009}_{\mathrm{sys}})\mathrm{GeV}.$ We use these moments to determine non-perturbative parameters governing the semileptonic width. In particular, we extract the heavy quark expansion parameters $\overline{\ensuremath{\Lambda}}=(0.39\ifmmode\pm\else\textpm\fi{}{0.03}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.06}_{\mathrm{sys}}\ifmmode\pm\else\textpm\fi{}{0.12}_{\mathrm{th}})\mathrm{GeV}$ and ${\ensuremath{\lambda}}_{1}=(\ensuremath{-}0.25\ifmmode\pm\else\textpm\fi{}{0.02}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.05}_{\mathrm{sys}}\ifmmode\pm\else\textpm\fi{}{0.14}_{\mathrm{th}}){\mathrm{GeV}}^{2}.$ The theoretical constraints used are evaluated through order ${1/M}_{B}^{3}$ in the non-perturbative expansion and ${\ensuremath{\beta}}_{0}{\ensuremath{\alpha}}_{s}^{2}$ in the perturbative expansion. We use these parameters to extract $|{V}_{\mathrm{cb}}|$ from the world average of the semileptonic width and find $|{V}_{\mathrm{cb}}|=(40.8\ifmmode\pm\else\textpm\fi{}{0.5}_{{\ensuremath{\Gamma}}_{\mathrm{sl}}}\ifmmode\pm\else\textpm\fi{}{0.4}_{({\ensuremath{\lambda}}_{1},\overline{\ensuremath{\Lambda}}{)}_{\mathrm{exp}}}\ifmmode\pm\else\textpm\fi{}{0.9}_{\mathrm{th}})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}.$ In addition, we extract the short range b-quark mass ${m}_{b}^{1\mathrm{S}}=(4.82\ifmmode\pm\else\textpm\fi{}{0.07}_{\mathrm{exp}}\ifmmode\pm\else\textpm\fi{}{0.11}_{\mathrm{th}})\mathrm{GeV}{/c}^{2}.$ Finally, we discuss the implications of our measurements for the theoretical understanding of inclusive semileptonic processes.
We report on a search for the radiative decay Upsilon(1S)-->gammaeta(') in 61.3 pb(-1) of data taken with the CLEO II detector at the Cornell Electron Storage Ring. Three decay chains were investigated, all involving eta(')-->pi(+)pi(-)eta, followed by eta-->gammagamma, eta-->pi(0)pi(0)pi(0), or eta-->pi(+)pi(-)pi(0). We find no candidate events in any of the three cases and set a combined upper limit of 1.6x10(-5) at 90% C.L., significantly smaller than the previous limit. We compare our result to other radiative Upsilon decays, to radiative J/psi decays, and to theoretical predictions.
We have measured the CP asymmetry A(CP) identical with[gamma(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.
We determine the weak coupling /V(cb)/ between the b and c quarks using a sample of 3 x 10(6) BB; events in the CLEO detector at the Cornell Electron Storage Ring. We determine the yield of reconstructed B-->D*l nu; decays as a function of w, the boost of the D* in the B rest frame, and from this we obtain the differential decay rate d Gamma/dw. By extrapolating d Gamma/dw to w=1, the kinematic end point at which the D* is at rest relative to the B, we extract the product /V(cb)/F(1), where F(1) is the form factor at w=1. Combined with theoretical results for F(1) we determine /V(cb)/=0.0469+/-0.0014(stat)+/-0.0020(syst)+/-0.0018(theor).
We report results of a search for B-->tau(nu) in a sample of 9.7 x 10(6) charged B meson decays. We exclusively reconstruct the companion B decay to suppress background. We set an upper limit on the branching fraction B(B-->tau(nu))<8.4 x 10(-4) at 90% confidence level. We also establish B(B+/--->K+/-nu(nu))<2.4 x 10(-4) at 90% confidence level.
A search has been made for neutrinos from the hep reaction in the Sun and from the diffuse supernova neutrino background (DSNB) using data collected during the first operational phase of the Sudbury Neutrino Observatory, with an exposure of 0.65 kilotonne-years. For the hep neutrino search, two events are observed in the effective electron energy range of 14.3 MeV
We have performed three searches for high-frequency signals in the solar neutrino flux measured by the Sudbury Neutrino Observatory (SNO), motivated by the possibility that solar $g$-mode oscillations could affect the production or propagation of solar $^8$B neutrinos. The first search looked for any significant peak in the frequency range 1/day to 144/day, with a sensitivity to sinusoidal signals with amplitudes of 12% or greater. The second search focused on regions in which $g$-mode signals have been claimed by experiments aboard the SoHO satellite, and was sensitive to signals with amplitudes of 10% or greater. The third search looked for extra power across the entire frequency band. No statistically significant signal was detected in any of the three searches.
We report on determinations of |Vub| resulting from studies of the branching fraction and q^2 distributions in exclusive semileptonic B decays that proceed via the b->u transition. Our data set consists of the 9.7x10^6 BBbar meson pairs collected at the Y(4S) resonance with the CLEO II detector. We measure B(B0 -> pi- l+ nu) = (1.33 +- 0.18 +- 0.11 +- 0.01 +- 0.07)x10^{-4} and B(B0 -> rho- l+ nu) = (2.17 +- 0.34 +0.47/-0.54 +- 0.41 +- 0.01)x10^{-4}, where the errors are statistical, experimental systematic, systematic due to residual form-factor uncertainties in the signal, and systematic due to residual form-factor uncertainties in the cross-feed modes, respectively. We also find B(B+ -> eta l+ nu) = (0.84 +- 0.31 +- 0.16 +- 0.09)x10^{-4}, consistent with what is expected from the B -> pi l nu mode and quark model symmetries. We extract |Vub| using Light-Cone Sum Rules (LCSR) for 0<= q^2<16 GeV^2 and Lattice QCD (LQCD) for 16 GeV^2 <= q^2 < q^2_max. Combining both intervals yields |Vub| = (3.24 +- 0.22 +- 0.13 +0.55/-0.39 +- 0.09)x10^{-3}$ for pi l nu, and |Vub| = (3.00 +- 0.21 +0.29/-0.35 +0.49/-0.38 +-0.28)x10^{-3} for rho l nu, where the errors are statistical, experimental systematic, theoretical, and signal form-factor shape, respectively. Our combined value from both decay modes is |Vub| = (3.17 +- 0.17 +0.16/-0.17 +0.53/-0.39 +-0.03)x10^{-3}.
