Experimental study of muon bundles observed in the Fréjus detector.
The present study is based on a sample of 407 775 single muons and 12 559 muon bundles with zenith angles smaller than 60{degree}, observed in the 12.3 m{times}6 m{times}6 m Frejus proton-decay detector, at a depth of 4850 hg/cm{sup 2}. The variation of the vertical muon intensity with depth is given. Using a maximum-likelihood method, the muon lateral distribution of underground bundles is investigated as a function of muon multiplicity and zenith angle. The same method yields the true multiplicity distribution at the site depth, corrected for all detection effects.

title: Separating γ- and hadron-induced cosmic ray air showers with feed-forward neural networks using the charged particle information⋆
abstract: The success of current and future air shower arrays in detecting point sources of cosmic rays above 10 TeV depends crucially on the possibility of finding efficient methods for separating γ-induced air showers from the overwhelming background of hadron-induced showers. We study the application of computer-simulated feed-forward neural networks in the analysis of cosmic ray data taken with the Geiger towers of the HEGRA air shower array. The combination of these charged particle detectors with the neural net based analysis is characterized by high background rejection and signal efficiency. In contrast to the often-quoted non-transparency of the net technique, the detailed analysis of the net performance gives insight into the physics involved and helps to asses the different information that allow γ/hadron separation

title: Inclusive muon production at PETRA energies

title: Status of the Fréjus experiment and preliminary results on contained events
abstract: SummaryWe will report, in this paper, the present status of the Fréjus experiment and the preliminary results obtained in the search for nucleon decay.RiassuntoSi riporta in questo lavoro lo stato attuale dell'esperimento del Fréjus e i risultati preliminari ottenuti nella ricerca del decadimento nucleonico. работе описывается современное состояние эксперимента в туннеле «Фреджас» и предварительные результаты по поиску распада нуклона.

title: Measurements of Tau-Lepton production and decay
abstract: We have studied 419 τ pair events produced in the reactione+e−→τ+ τ− at a c.m. energy of 34.6 GeV. We measure the cross section and angular distribution, as well as the decay branching ratios. The production characteristics are consistent with the Standard Electroweak Model predictions of γ andZ0 interference. The branching ratios are generally consistent with the τ decaying according to standard weak interaction principles, but we observe somewhat more decays resulting in single charged hadrons plus neutrals than are predicted by present theory.

title: Anomalous Muon Production in e+ e- Annihilation as Evidence for Heavy Leptons
abstract: We have measured inclusive muon production in e + e − annihilation for CMS energies between 3.6 and 5.0 GeV. Above 4 GeV the cross section cannot be explained by conventional sources like higher order QED processes or inclusive production of the J ϑ (3.1). It is, however, compatible with the pair production of heavy particles of a mass of about 1.9 GeV/ c 2 . Spin assignment and decay parameters are investigated.

title: Reaction rate for destruction of 7Li and primordial nucleosynthesis.
abstract: The rate for destruction of [sup 7]Li via deuteron-induced reactions is reexamined and is found to be appreciably larger than that previously used in primordial nucleosynthesis codes over most of the temperature region of interest. Numerous calculations were run to determine the significance of the new rate; it was found to change the predicted [sup 7]Li abundance by not more than 20% over the parameter space examined.

title: Space-time as a causal set.
abstract: We propose that space-time at the smallest scales is in reality a causal set: a locally finite set of elements endowed with a partial order corresponding to the macroscopic relation that defines past and future. We explore how a Lorentzian manifold can approximate a causal set, noting in particular that the thereby defined effective dimensionality of a given causal set can vary with length scale. Finally, we speculate briefly on the quantum dynamics of causal sets, indicating why an appropriate choice of action can reproduce general relativity in the classical limit.