[en] A first analysis of the full data set collected by CHORUS in the years 1994-1997 is presented. The signal of ν_τ appearance in an almost pure ν_μ beam has been searched looking for τ leptons produced in ν_τ charged current interactions and their subsequent decay into both the leptonic and hadronic decay channels. No τ candidate has been found. A ν_μ → ν_τ mixing is excluded down to sin²2θ_μτ = 6.8 x 10^-4 for large Δm² (90% C.L.)

[en] The current status of neutrino physics is presented, with focus on the latest experimental results on neutrino masses and oscillation

[en] The measurement of the forward-backward heavy-quark asymmetry at LEP is presented. The present status of the experimental techniques is reviewed and the LEP averages are given for the b and c asymmetries. Averaging all LEP results including the lepton asymmetries, the τ-polarization and its asymmetry yields sin² θ_eff^lept = 0.2318 ± 0.0004. Combining this result with the SLC left-right asymmetry measurement gives sin² θ_eff^lept = 0.2313 ± 0.0003

[en] Using the L3 detector at LEP the cross section of single photon events has been measured in e⁺e^- collisions near the Z resonance. An integrated luminosity of 9.6 pb^-1 has been collected observing 202 single photons candidates with energy between 0.9 and 3.5 GeV. Assuming that the only stable, weakly interacting particles are light neutrinos with standard model couplings, the number of light neutrino species has been determined to be N_ν=3.14±0.24(stat)±0.08(sys). This corresponds to an invisible decay width of the Z into weakly interacting particles of Γ_inv=524±40±13 MeV. (author) 11 refs.; 6 figs.; 1 tab

[en] The detailed investigation of e⁺e^- annihilation around the Z resonance allows a high accuracy test of the Standard Model. The first set of precision experiments around the Z peak performed by the ALEPH, DELPHI, L3 and OPAL Collaborations are analyzed. A brief description of the line shape analysis is given, and a model independent fit to the e⁺e^- → hadrons, e⁺e^- → μ⁺μ^-, and e⁺e^- → τ⁺τ^- data is performed. A comparison with the Standard Model is also presented. (K.A.) 19 refs.; 2 figs.; 4 tabs

[en] We discuss an experimental technique aimed at tagging electron neutrinos in multi-GeV artificial sources on an event-by-event basis. It exploits in a novel manner calorimetric and tracking technologies developed in the framework of the LHC experiments and of rare kaon decay searches. The setup is suited for slow-extraction, moderate power beams and it is based on an instrumented decay tunnel equipped with tagging units that intercept secondary and tertiary leptons from the bulk of undecayed π⁺ and protons. We show that the taggers are able to reduce the ν_e contamination originating from K_e3 decays by about one order of magnitude. Only a limited suppression (∝60%) is achieved for ν_e produced by the decay-in-flight of muons; for low beam powers, similar performance as for K_e3 can be reached supplementing the tagging system with an instrumented beam dump. (orig.)

[en] The preliminary oscillation analysis of the complete K2K data set is presented, corresponding to 1.049x10²⁰ protons on target. The observed number of events and their energy spectrum are both consistent with neutrino oscillation. The probability these results are compatible with the no-oscillation hypothesis is 0.003% (4.19σ). The allowed regions of the oscillation parameters are consistent with the atmospheric measurements

[en] Absolute neutrino cross section measurements are presently limited by uncertainties on ν fluxes. In this paper, we propose a technique that is based on the reconstruction of large angle positrons in the decay tunnel to identify three-body semileptonic K⁺ → e⁺π⁰ν_e decays. This tagging facility operated in positron counting mode (gevent count mode h) can be employed to determine the absolute ν_e flux at the neutrino detector with O(1%) precision. Facilities operated in gevent by event tag mode h i.e. tagged neutrino beams that exploit the time coincidence of the positron at source and the ν_e interaction at the detector, are also discussed. (orig.)

[en] We summarize the discussion and presentation of new experimental results in low energy neutrino scattering at the NuInt05 workshop. In addition, we comment on several investigations that we would like to see targeted in preparation for the next NuInt workshop

[en] In this paper, we report on the measurement of the rate of inclusive π⁰ production induced by charged-current neutrino interactions in a C₈H₈ target at a mean energy of 1.3 GeV in the K2K near detector. Out of a sample of 11 606 charged-current neutrino interactions, we select 479 π⁰ events with two reconstructed photons. We find that the cross section for the inclusive π⁰ production relative to the charged-current quasielastic cross section is (σ_CCπ⁰/σ_CCQE)=0.426±0.032 (stat)±0.035 (syst). The energy-dependent cross section ratio is also measured. The results are consistent with previous experiments for exclusive channels on different targets.