[en] Up to 8 Ge detectors have been used to collect 11.2 kg.y of data in the search for neutrinoless double beta decay. Present half-life limits are (7 to 13) x 10²³y for the 0⁺ → 0⁺ transition and (2 to 3) x 10²³y for that from 0⁺ → 2⁺, where in each case the first number comes from the fluctuation in the background (about 1.4 counts/keV.kg.y at 2 MeV) and the second from a maximum likelihood analysis. One Ge detector has also been used to search for low energy recoils to set limits on the masses of weakly interacting massive particles which could constitute the dark matter of the galaxy and scatter from Ge nuclei

[en] In 1980 two experiments ignited a fertile field of research - the determination of the neutrino masses. Subsequently, over 35 experiments using a variety of techniques have probed or are probing this question. Primarily the author discuss electron antineutrino (hereafter referred to as neutrino) mass experiments. Section I begins with a discussion of astronomical and terrestrial observations which motivated these experiments. In Section II, the author quote limits from muon and tau mass determinations. These limits are more thoroughly discussed in other paper. The author continues by describing the four approaches used to measure the electron neutrino mass. In Section III, tritium beta decay mass determinations are reviewed. This section includes a general summary of previous experimental results, and discussion of the major ongoing experiments. Section IV offers concluding remarks

[en] ARGUS has been operating at the Doris II, e⁺e^- storage ring in DESY since the end of 1982. Some of the results from the data collected in 1983 and 1984, at the Upsilon(1S), Upsilon(2S), Upsilon(4S) resonances and in the nearby continuum, are reported here. The integrated luminosities and numbers of multihadron events collected at each energy are shown

[en] Partial lifetime limits for 34 modes of nucleon decay are presented for 417 live days of observation. In all cases the properties of the contained event sample are consistent with those expected of atmospheric neutrino interactions. Other physics results, including limits on the flux of GUT monopoles, the free proton lifetime, the anti n-n oscillation period, neutrino oscillation limits, and the upward muon flux, are also reported

[en] New results on the xi(2.2) are reported. Mark III has analyzed new J/phi data and reconfirmed the xi(2.2) in radiative J/phi decays to K/sub s/⁰ K/sub s/⁰ and K⁺K^-. The significances of the signals are 3.6 and 4.5 standard deviations, the masses, 2.232 +/- 0.007 +/- .007 and 2.230 +/- .006 +/- .014 GeV/c², and the widths, 0.018 +/- /sup +.023//sub -.015 +/- .010 and 0.026 +/- /sup +.020//sub -.016/ +/- .017 GeV/c², for the K/sub S/⁰ K/sub s/⁰ and K⁺K^- modes, respectively. The branching ratios are BR(J/phi → γxi,xi → K/sub s/⁰ K/sub s/⁰) = (3.2 +/-/sup +1.6//sub -1.3/ +/- 0.7) x 10^-5 and BR(J/phi → γxi,xi → K⁺K^-) = 4.2 /sup +1.7//sub -1.4/ +/- 0.8) x 10^-5

[en] An experiment carried out in the electron-positron storage ring VEPP-2M with the Neutral Detector has demonstrated the existence of the decay ω→π⁰e⁺e^- and has measured its relative probability BR(ω→π⁰e⁺e^-) = (0.59 +- 0.19)x10^-3. An upper limit has also been established for the probability of the decay phi→π⁰e⁺e^-: BR(phi→π⁰e⁺e^-)<1.2x10^-4

[en] This thesis describes how the decay W^± → μ^± ν was identified in the UA1 experiment at a centre of mass energy of 630 GeV. An analysis of the W^± events is discussed in terms of the Standard Model. In the third chapter, the UA1 experiment is described, with emphasis placed on the muon detector. The fourth chapter explains the methods used for muon identification. The fifth chapter gives an application of these methods, a measurement of the inclusive p_T spectrum. Known muon and muon background sources are summarized. The sixth chapter deals with the W^± → μ^±ν selection, concentrating on acceptance and background calculations. In the subsequent chapter, the decay and production properties of the intermediate vector bosons are discussed in the frame work of the Standard Model. The W^± → μ^±ν sample is used to determine cross section times branching ratio and the mass of the W^±. Results are compared with findings in the electron decay channel. Both electron and muon samples are combined in the further analysis. Parameters of the Standard Model are determined from the masses of the intermediate vector bosons and are compared to theoretical predictions and measurements from other experiments. The angular distribution of the leptons from the W^± decay provides a confirmation of parity violation in electroweak interactions. From the ratio of σ.B of W^± and Z⁰ a limit on the number of light neutrino species is derived. (orig./HSI)

[en] Using the ARGUS detector at the e⁺e^- storage ring DORIS II, we have measured the average polarization of D^*+ mesons originating from exclusive decays anti B⁰ → D^*+l^-anti ν. By comparing the D^*+ decay angular distribution to a functional form 1+αcos²θ, we determine α to be α = 0.7±0.9. This value of α leads to a ratio of longitudinal to transverse decay width Γ_L/Γ_T = 0.85±0.45, which allows the determination, vertical strokeV_cbvertical stroke=0.052±0.011. The importance of the transverse helicity component is manifested in the q² and lepton spectra, which are also presented. (orig.)

[en] Recent results are reported from the ARGUS and Crystal Ball experiments, operating at the DORIS II e⁺e^- storage ring at DESY. Addressing the problem with the branching ratios of the 1-prong τ decays a precise measurement of BR (τ^- → ν_τ π^-π⁰π⁰) = (6.6 ± 0.7 ± 1.7)% was performed. No evidence was found for the decay τ^- → ν_τπ^-η. This supports the absence of second class currents in τ decays. Many results concerning the weak interactions of b quarks have been obtained from the investigation of B meson decays. The exclusive semileptonic branching ratio BR (B⁰ → D^*-l⁺ν_l) = (7.0 ± 1.2 ± 1.9)% has been measured as well as the inclusive semileptonic branching ratio. First evidence for charmless B decays was found in the channels B⁺ → p anti pπ⁺ and B⁰ → p anti pπ⁺ π^- with the branching ratios BR (B⁺ → p anti pπ⁺) = (0.037 ± 0.013 ± 0.014)% and BR (B⁰ →p anti pπ⁺π^-) = (0.060 ± 0.020 ± 0.022)%. This yields a lower limit for /V_ub/V_cb/ ≥ 0.07. Finally B⁰ - anti B⁰ mixing was observed with three different analysis methods. The combined result for the mixing parameter is τ = 0.21 ± 0.08. This puts a serious constraint on some parameters of the standard model

[en] The last year has brought such a wealth of new information on heavy flavors that meaningful bounds can now be placed on all fermion mass related parameters in the Standard Model. I review the status of the KM matrix with particular emphasis on the theoretical uncertainties. B⁰ - anti B⁰ mixing is reevaluated and CP violation is discussed as it is observed in K_L decays and as it hopefully can be studied in B decays. I conclude with short remarks on neutrino oscillations