The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric Standard Model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The combined LEP data show no significant excess of events which would indicate the production of Higgs bosons. The search results are used to set upper bounds on the cross-sections of various Higgs-like event topologies. The results are interpreted within the MSSM in a number of "benchmark" models, including CP-conserving and CP-violating scenarios. These interpretations lead in all cases to large exclusions in the MSSM parameter space. Absolute limits are set on the parameter tan β and, in some scenarios, on the masses of neutral Higgs bosons.

In this Report, QCD results obtained from a study of hadronic event structure in high energy e+e− interactions with the L3 detector are presented. The operation of the LEP collider at many different collision energies from 91 to 209 GeV offers a unique opportunity to test QCD by measuring the energy dependence of different observables. The main results concern the measurement of the strong coupling constant, alpha_s, from hadronic event shapes and the\ud study of effects of soft gluon coherence in charged particle multiplicity and momentum distributions

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Validation of the reference sample method (RSM) in the rat was accomplished by: 1) simultaneous measurement of cardiac output (CO) by the RSM and electromagnetic flowmetry method in ether-anesthetized open-chest Wistar rats, and 2) determination of systemic and regional hemodynamic reproducibility in conscious rats following three serial injections of microspheres. The optimal sampling time and sampling rate were determined in several CO states. The results indicate that: 1) 200 or more microspheres contained in the reference sample result in an accurate determination of CO, 2) almost 100% of the microspheres are trapped by tissues with in 20 s of cessation of the microsphere injection, 3) the hemodynamic steady state is affected only under low cardiac output conditions at a high sampling rate (1.211 ml/min), 4) three repeated injections of microspheres in conscious animals do not alter systemic hemodynamis, and 5) the reproducibility of regional blood flow distribution is good in all organs except the liver, stomach, spleen, and skin (third application). These data indicate that the RSM is reliable, providing reasonable accuracy and reproducibility of systemic and regional hemodynamics in the rat.

Single- and multi-photon events with missing energy are selected in 619 pb−1 of data collected by the L3 detector at LEP at centre-of-mass energies between 189 GeV and 209 GeV. The cross sections of the process e+e− → vv-bar gamma (gamma) are found to be in agreement with the Standard Model expectations, and the number of light neutrino species is determined, including lower energy data, to be N = 2.98 +/- 0.05 +/- 0.04.\ud Selection results are given in the form of tables which can be used to test future models involving single- and multi-photon signatures at LEP. These final states are also predicted by models with large extra dimensions and by several supersymmetric\ud models. No evidence for such models is found. Among others, lower limits between 1.5 TeV and 0.65 TeV are set, at 95% confidence level, on the new scale of gravity for the number of extra dimensions between 2 and 8