No abstract

No abstract

A missing-mass search has been made for negatively charged boson resonances Bproduced in the reaction n -p -+B-p at beam momenta of 40, 100, 200, and 240 GeV. Approximately 600 000 events were included in the final mass spectra. In the mass region 2 5 IM, 5 12.5 GeV no statistically significant enhancements were observed. The 5-standard-deviation upper limit on the production of narrow resonances is of the order of 10 pb for 2 5 M, 5 10.5 GeV.

In a search for charmed particles the reactions TT~ +p ~^p r +ju +X and p +p ~^p r +JU +X have been studied at beam energies of 200 and 240 GeV, respectively. Measurements of the beam particle and the slow recoil proton, p rt were used to reconstruct the mass (M) of the JU +X system. Model-dependent upper limits, sensitive to threshold behavior, are presented for the forward production cross section times the muon branching ratio for high-mass states (6 < M 2 < 54 GeV 2 ). This Letter reports the results of a charm search experiment which measured the reactions v-+p-p r +Y,

Data on the inclusive production of the neutral vector mesons rho(0)(770), omega(782), K*(0)(892), and phi (1020) in hadronic Z decays recorded with the ALEPH detector at LEP are presented and compared to Monte Carlo model predictions. Bose-Einstein effects are found to be important in extracting a reliable value for the p(0) production rate. An average p(0) multiplicity of 1.45 +/- 0.21 per event is obtained. The omega is detected via its three pion decay mode omega --> pi(+)pi(-)pi(0) and has a total rate of 1.07 +/- 0.14 per event. The multiplicity of the K*(0) is 0.83 +/- 0.09, whilst that of the phi is 0.122 +/- 0.009, both measured using their charged decay modes. The measurements provide information on the relative production rates of vector and pseudoscalar mesons, as well as on the relative probabilities for the production of hadrons containing u, d, and s quarks