A measurement of the $\mathrm{K^0_s}$ and $\Lambda$ inclusive production rates and momentum spectra in two- and three-jet events is presented. On the basis of about 3.1~million Z decays collected ...with the L3 detector at LEP, we observe that the production of these particles is well modeled by string fragmentation.
A search for unstable sequential neutral and charged heavy leptons has been made at center-of-mass energies 130 and 136 \GeV\ with the L3 detector at LEP. The neutral leptons are assumed to decay via ...mixing to electrons and muons. No evidence for their existence was found. We exclude unstable Dirac neutrinos for masses below 59.3 (57.9) \GeV\ and unstable Majorana neutrinos below 48.6 (47.2) \GeV\ if the neutrino couples to the electron(muon) family. We exclude unstable charged heavy leptons for masses below 61 \GeV\ for a wide range of the associated neutral lepton m
We report on a search for the excited leptons e^*,mu^*,tau^* and nu^* in e+e- collisions at sqrt{s} = 130 - 140 GeV using the L3 detector at LEP. No evidence has been found for their existence. From ...an analysis of the expected pair produced l^*l^* in the channels e.e.gamma.gamma, mu.mu.gamma.gamma, tau.tau.gamma.gamma, eeWW, and nu.nu.gamma.gamma, we determine the lower mass limits at 95% C.L. of 64.7 GeV for e^*, 64.9 GeV for mu^*, 64.2 GeV for tau*, 57.3 GeV ( eW decay mode) and 61.4 GeV ( nu.gamma decay mode) for nu^*. From an analysis of the expected singly produced l.l^* in the channels e.e.gamma, mu.mu.gamma, tau.tau.gamma, nu.eW and nu.nu.gamma, we determine upper limits on the couplings lambda/m_{l^*} up to m_{l^*} = 130 GeV
The reactions γγ→π+π−π+π− and γγ→π+π0π−π0 are studied with the L3 detector at LEP in a data sample collected at centre-of-mass energies from 161 GeV to 209 GeV with a total integrated luminosity of ...698 pb−1. A spin-parity-helicity analysis of the ρ0ρ0 and ρ+ρ− systems for two-photon centre-of-mass energies between 1 and 3 GeV shows the dominance of the spin-parity state 2+ with helicity 2. The contribution of 0+ and 0− spin-parity states is also observed, whereas contributions of 2− states and of a state with spin-parity 2+ and zero helicity are found to be negligible.
The reactions gamma gamma -> pi^+pi^-pi^+pi^- and gamma gamma -> pi^+pi^0pi^-pi^0 are studied with the L3 detector at LEP in a data sample collected at centre-of-mass energies from 161GeV to 209GeV ...with a total integrated luminosity of 698/pb. A spin-parity-helicity analysis of the rho^0 rho^0 and rho^+ rho^- systems for two-photon centre-of-mass energies between 1GeV and 3GeV shows the dominance of the spin-parity state 2+ with helicity 2. The contribution of 0+ and 0- spin-parity states is also observed, whereas contributions of 2- states and of a state with spin-parity 2+ and zero helicity are found to be negligible.
We measure three-particle Bose–Einstein correlations in hadronic Z decay with the L3 detector at LEP. Genuine three-particle Bose–Einstein correlations are observed. By comparing two- and ...three-particle correlations we find that the data are consistent with fully incoherent pion production.
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