[en] The theoretical justification and results from recent experimental searches for backward-produced exotic mesons including two experiments carried out by the collaboration at SLAC are reviewed. The first experiment put upper limits of about 1 to 2 μb for X⁺⁺ → (2π, 4π, 6π)⁺⁺ and anti ppπ⁺π⁺ in the reaction π⁺ + p → X⁺⁺ + n/sub forward/ at 8.4 GeV/c studied with the SLAC 14 inch rapid cycling bubble chamber triggered by a downstream neutron detector. Also the important features of the recently completed second experiment with the SLAC streamer chamber to study the reaction π^- + p → X^-- + p/sub forward/ at 14 GeV/c are discussed

[en] We report on π^-N events observed at 150 and 175 GeV/c in a large-acceptance spectrometer triggered by J/psi→μμ. We observe with high mass-resolution the particles psi', K⁰ and Λ. We present evidence for a new resonance at 5.3 GeV/c², whose possible interpretation is a meson containing a b-quark

[en] A search has been made with the upgraded UA2 experiment at the CERN anti pp Collider at √s=630 GeV for multi-jet events with large transverse momentum imbalance in a data sample corresponding to an integrated luminosity of 7.4 pb^-1. Under the assumption that the photino is the lightest stable supersymmetric (SUSY) particle, the data have been used to deduce lower limits in a minimal SUSY model for the squark (m_q) and the gluino (m_g) masses. The 90% CL bounds are m_g>74 GeV independent of m_g, m_g>79 GeV indpendent of m_g, and m>106 GeV for m_q=m_q=m. (orig.)

[en] Results on the production cross sections of W and Z bosons detected in the UA2 experiment are given based on a large sample of W→eν and Z→e⁺e^- decays. The measured cross sections are σ_W^e=660±15(stat)±37(syst) pb, σ_Z^e=70.4±5.5(stat)±4.0(syst) pb and their ratio R=9.38_-0.72^+0.82(stat)±0.25(syst). In the framework of the Standard Model, the measured value of R is used to determine the total width of the W, Γ(W)=2.30±0.19(stat)±0.06(syst) GeV. (orig.)

[en] The transverse momentum distributions of W and Z bosons produced in anti pp collisions at √s=630 GeV are examined. Comparisons are made with QCD predictions, and good agreement is found. The fraction of W bosons produced with p_T>25 GeV is found to be 3.8±0.6(stat)_-1.3^+0.9(syst)%. (orig.)

[en] The ratio of branching fractions of the W decaying to τ and e leptons is measured using anti pp collisions at √s=630 GeV. The ratio of the electroweak charged current couplings to the W is then determined to be g_τ^W/g_e^W=0.997±0.056(stat.)±0.042(syst.). The decay mode Z→τ⁺τ^- is observed and also found to be consistent with e-τ universality. (orig.)

No abstract available

[en] In a large-acceptance spectrometer, μ⁺μ^- muon pairs and associated hadrons were observed with μμ masses up to 10 GeV/c² and ΔM/M=0.015 resolution. It is reported here on the production of 700 J/psi and 140 psi' mesons; preliminary results on hadrons associated with these mesons are also given

[en] The Z⁺⁺₁(3507) and the Z⁺⁺₂(3553) states have been observed in the Goliath spectrometer at the CERN SPS in 185 GeV/c π^- -Be collisions. Their radiative decays contribute 27.7% (for the Z⁺⁺₁) and 12.8% (for the Z⁺⁺₂) to J/psi production. At this energy, their cross sections are 65 +- 19 nb and 96 +- 29 nb, respectively. (orig.)

[en] A study of the two-jet mass spectrum measured with the UA2 calorimeter has revealed a signal from hadronic decays of W and Z bosons above a large background. Production and decay properties of the signal have been measured. The combined production cross-section σ.B (W, Z→two jets) is 9.6±2.3(stat.)±1.1(syst.) nb, compared with an expectation of 5.9 nb calculated to order α_s². A limit on the production cross-section of additional heavy vector bosons decaying into two jets is given as a function of the boson mass. (orig.)