[en] The N(e,e'γ) reaction is investigated to find the N-Δ transition quadrupole moment. The cross section is expressed in terms of N-Δ transition form factors, and it shows a typical dipole radiation pattern if the quadrupole moment vanishes. Given a finite transition quadrupole moment, the dipole radiation pattern rotates. In the laboratory frame, the radiation is peaked in the forward direction due to the Δ motion. Measurement in the out-of-scattering plane is suggested to find the quadrupole moment

[en] Published in summary form only

No abstract available

[en] The basic concepts and hypotheses used for describing electron-nucleus scattering are reviewed together with the nuclear information drawn from scattering cross sections

[en] In high-energy electron-nucleus scattering, a new quantity for characterizing the additional information about the structure of a nuclear transition contained in the current distributions is defined, the vorticity density. It is symmetrical between the states involved in the transition, and it is completely unconstrained by the transition charge distribution. It is evaluated and discussed for single-particle harmonic oscillator transitions, for hydrodynamic collective transitions, and then for 3^- transitions in ²⁰⁸Pb as described by the random phase approximation. Its relationship to collectivity is discussed. (orig.)

[en] Published in summary form only

[en] Recent papers have discussed the possibility that a spontaneously broken symmetry is restored at high magnetic fields. Possible evidence in favour of this idea is noted. (Auth.)

[en] First positron annihilation measurements are reported on high T_c superconductor YBa₂Cu₃O_7-x. The lifetime and Doppler broadening spectra show a slight but significant change about 240K suggesting a deviation from the normal structure far above 90K where the resistance falls to zero. (author)

No abstract available

No abstract available