[en] We examine the single-particle formalism used to describe neutrino interactions. A null-plane quantization scheme is used. We set up the general formalism as well as some techniques needed to perform phenomenological calculations. The single-particle formalism developed by Wolfenstein is recovered at the cost of making several approximations, the validity of which is discussed. (author)

[en] This paper presents a proposal to extend the present Beijing Electron Positron Collider into a Tau Charm Factory. To achieve this aim the author points out that a number of things need to come together, and to be successfully communicated to the Chinese government. Such a machine is a logical extension of the present BEPC device. The physics which can be accomplished at such a device, is important, and cannot be duplicated in planned meson factories, due to the presence of resonances and thresholds which allow minimization of systematic errors. The author stresses the need for international coorperation on this project, to have hope of it coming to fruition. The whole concept of such a Tau Charm Factory needs more support from the high energy physics community

[en] Direct and indirect evidence for the existence of a new heavy quark b and of new heavy neutral leptons N/sub e/ and N/sub μ/ can be sought in neutrino and e⁺e^- scattering. These particles are expected to have right-handed currents. Discussion is given on the characteristics, production and decay of hadrons such as bb, ub and db, and of the massive neutral leptons. Muon number violation with and without N/sub e/ and N/sub μ/ is considered

[en] The VEPP-4M electron-positron collider is now operating with the KEDR detector for the experiment of precise measurement of tau-lepton mass. In this experiment, monitoring of beam energy spread is important to know the energy spread contribution into the total systematic error. Information about the energy spread gives an opportunity to reduce the error of the tau-lepton mass measurement. Several techniques for energy spread measurement are described in the paper. Width of the ψ' resonance measured with the KEDR detector is used as a reference

[en] The neutrino working group addressed five general topics of interest to the neutrino community. These were nu/sub μ/e scattering, nu/sub e/e scattering, nu oscillation, nu/sub μ/P scattering and neutrino-nuclear reactions

[en] This paper presents the results of studies undertaken at INP of options for a Tau Charm Factory. Three different beam options have been studied. First is a 'round beam option', allowing axially symmetric beams which yield high tau-pair productivity. The second option involves monochromatic beams, which enhances productivity for narrow c bar c states, gives good tau pair productions in a clean manner, and has a good resonant-to-nonresonant ratio. The third option allows longitudinal polarization, should it prove to be interesting. It is an easy option to implement because it only involves polarized electrons. Work on some of these options is described in terms of experiments on the VEPP-2 device

[en] Next-to-next-to-leading contributions to the cross section σ(e⁺e^- → τ⁺τ^-) at energies close to threshold are analysed, taking into account the known non-relativistic effects and O(α²) corrections. The numerical changes with respect to previous works are small, but the new corrections give a true estimate of the uncertainty in the theoretical calculation

No abstract available

[en] We present a general analysis of the effective potential for neutrino propagation in matter, assuming a generic set of Lorentz invariant non-derivative interactions. We find that in addition to the known vector and axial vector terms, in a polarized medium also tensor interactions can play an important role. We compute the effective potential arising from a tensor interaction. We show that the components of the tensor potential transverse to the direction of the neutrino propagation can induce a neutrino spin flip, similar to the one induced by a transverse magnetic field. copyright 1999 The American Physical Society

[en] The major activities of the High Energy Physics Group at the Univ. of Maryland during the current contract period, that began five months ago, have been: construction and installation of modifications to PLUTO for 2γ physics, continued analyses of e⁺e^- events taken by the PLUTO detector at PETRA, analyses of high energy neutrino-deuterium interactions from the Fermilab 15' bubble chamber run, final analysis of the ν/sub μ/e elastic scattering experiment at Fermilab, assembly and first test run of the hadron jet experiment at Fermilab, tests with the neutron dipole apparatus and new cold neutron source at Argonne, and participation in two major large proposals on e-p collider experiment at Fermilab or Brookhaven, and a neutrino detector facility at Los Alamos