An enhancement near threshold is observed in the omega(phi) invariant mass spectrum from the doubly Okubo-Zweig-Iizuka-suppressed decays of J/psi-->gamma(omega)phi, based on a sample of 5.8 x 10(7) J/psi events collected with the BESII detector. A partial wave analysis shows that this enhancement favors JP=0+, and its mass and width are M=1812(+19)(-26)(stat)+/-18(syst) MeV/c2 and Gamma=105+/-20(stat)+/-28(syst) MeV/c2. The product branching fraction is determined to be B(J/psi-->gammaX)B(X-->omega(phi))=[2.61+/-0.27(stat)+/-0.65(syst)]x10(-4).

We have measured inclusive distributions for charged particles in hadronic decays of the Z boson. The variables chosen for study were charged-particle multiplicity, scaled momentum, and momenta transverse to the sphericity axes. The distributions have been corrected for detector effects and are compared with data from e'^e~ annihilation at lower energies and with the predictions of several QCDbased models. The data are in reasonable agreement with expectations.PACS numbers: 13.87.Fh In this Letter we present measurements of chargedparticle inclusive distributions in hadronic decays of the Z boson. These distributions allow us to study hadron production at higher energies than were previously available in e'^e~ annihilation. The leading theory of the strong interactions, QCD, predicts that many hadronization properties will have a logarithmic dependence on the center-of-mass energy (Ec.mX Hence, comparisons of data from a wide range of -fc.m. values are of interest for testing these predictions. The data presented here were taken with the Mark II detector at the SLAC e^e~ Linear Collider (SLC) running at several ^c.m values near the Z-boson resonance peak at 91.

We have searched for events with new-particle topologies in 390 hadronic Z decays with the Mark II detector at the SLAC Linear Collider. We place 95%-confidence-level lower limits of 40.7 GeV /c 2 for the top-quark mass, 42.0 GeV/c 2 for the mass of a fourth-generation charge -t quark, and 41.3GeV /c 2 for the mass of an unstable Dirac neutral lepton. PACS numbers: 13.38.+c, 12.15.Ff, 14.60.Gh, 14.80.Dq widths given by the standard model. We have searched for new quarks and leptons in Zboson decay using data from the Mark II detector at the SLAC e + e -Linear Collider (SLC) operating in the e + e-center-of-mass energy (E c.m) range from 89.2 to 93.0 GeV. The standard model predicts the existence of the top quark and does not exclude the possibility of new generations of fermions. The existence and masses of these possible new particles may provide information to help understand the pattern of fermion masses and the presence of generations.We specifically search for top (t) Ge V /c 2 by the VENUS Collaboration 5 at the KEK e + e -storage ring TRISTAN.We restrict our L 0 search to a sequential fourthgeneration Dirac neutral lepton. We assume that MLo We have investigated three types of event topologies. Type I is an event with an isolated charged track. The semileptonic decays of t and b' or the decays of L 0 will produce isolated leptons. To keep detection efficiencies high, lepton identification is not used. The type-2 topology is an event with an isolated photon. The decay b'-br motivates the search for this topology. Type 3 is the topology produced by a pair of heavy objects each decaying hadronically into two or more jets. Massive particles decaying into jets tend to produce spherical events which can be characterized by large momentum sums out of the event plane. The decay b'-+ b + gluon, t decaying through H + b, with the H + decaying 100% hadronically, and the CC hadronic decays oft and b' are examples.Details of the Mark II detector can be found elsewhere. 7 A cylindrical drift chamber in a 4.75-kG axial magnetic field measures charged-particle momenta. Photons are detected in electromagnetic calorimeters covering the angular region I coslJ I < 0.96, where lJ is the angle with respect to the beam axis. Barrel leadliquid-argon sampling calorimeters cover the central region I coslJ I < 0. 72 and the remaining solid angle is covered by end-cap lead-proportional-tube calorimeters. The detector is triggered by two or more charged tracks within I cos9l < 0. 76 or by neutral-energy requirements of a single shower depositing at least 3.3 GeV in the barrel calorimeter or 2.2 GeV in an end-cap calorimeter. This combination results in an estimated trigger efficiency of greater than 99% for hadronic Z decays.All three types of event topologies share the following event-selection criteria: Charged tracks are required to project into a cylindrical volume of radius 1 em and halflength of 3 em around the nominal collision point parallel to the beam axis, to be within the angular region 2448 I coslJ I < 0.85, and to ...