121467224
PARITY NONCONSERVATION IN NUCLEI
BS>The influence of the known weak interactions on the parity of nuclear states is discussed. Derivation of a parity nonconserving interaction rests on the assumption of a current-current hypothesis for the weak interactions. Consequently, observation of parity impurity effects would be an important confirmation of this hypothesis. A simple approximate method of treating the nuclear parity impurity is developed and applied in an effort to find experimental situations favorable to observation of effects due to such impurity. Parity-forbidden alpha decay from excited states of light nuclei and certain electromagnetic transitions in the heavy nuclei appear to be promising. Special attention was paid to the internal conversion electrons from the 123kev transition nn Lu/sup 173/ whose polarization is estimated to be about 0.4%. An effect on polarized neutrons analogous to optical rotation is also discussed. (auth)
123416974
Theory of pulsar magnetospheres
There is a wide range of fundamental physical problems directly related to how pulsars function. Some of these are independent of the specific pulsar mechanism. Others relate directly to the physics of the pulsar and already shed some light on the properties of matter at high density (\ensuremath{\sim}${10}^{15}$ g/cc) and in strong magnetic fields (\ensuremath{\sim}${10}^{12}$ G). Pulsars are assumed to be rotating neutron stars surrounded by strong magnetic fields and energetic particles. It is somewhere within this "magnetosphere" that the pulsar action is expected to take place. Currently there has been considerable difficulty in formulating an entirely self-consistent theory of the magnetospheric behavior and there may be rapid revisions in the near future, which is all the more surprising since many of the issues involve "elementary" problems in electromagnetism. One interesting discovery is that charge-separated plasmas apparently can support stable static discontinuities.
118496663
Gravitating superconducting strings with timelike or spacelike currents
We construct gravitating superconducting string solutions of the $U(1{)}_{\mathrm{local}}\ifmmode\times\else\texttimes\fi{}U(1{)}_{\mathrm{global}}$ model by solving the coupled system of Einstein and matter field equations numerically. We study the properties of these solutions in dependence on the symmetry breaking to Planck mass ratio. Using the macroscopic stability conditions formulated by Carter, we observe that the coupling to gravity allows for a new stable region that is not present in the flat space-time limit. We match the asymptotic metric to the Kasner metric and show that the relations between the Kasner coefficients and the energy per unit length and tension suggested previously are well fulfilled for symmetry breaking scale much smaller than the Planck mass. We also study the solutions to the geodesic equation in this space-time. While geodesics in the exterior space-time of standard cosmic strings are just straight lines, test particles experience a force in a general Kasner space-time, and as such, bound orbits are possible.
34169460
Luneburg lens approach to nuclear rainbow scattering.
The physical interpretation of nuclear rainbow scattering within the frame of the optical model is critically investigated. Starting from the properties of the Luneburg lens, a gradient index device that displays refractive features similar to those of the nuclear potential, important differences between the mechanisms producing the nuclear and optical rainbows are pointed out.
124193977
High-spin states in Ne-20 reached by O-16 (alpha, alpha) O-16 elastic scattering
119969931
Optical-model Description of Alpha+o-16 Elastic-scattering and Alpha-cluster Structure in Ne-20
O16(,) elastic scattering angular distributions have been measured for incident energies 39.3, 49.5, and 69.5 MeV. These data, and previous measurements at 32.2, 104, and 146 MeV, have been subjected to a global optical model analysis. The deduced global potential has two energy-dependent parameters which are found to vary smoothly with energy and it is uniquely determined by the data. Backward angular distributions measured between 40 and 54 MeV are also presented and shown to be nicely reproduced by the model. The sensitivity of the cross sections to the various regions of the real potential has been investigated as a function of energy using the notch test technique. The low energy behavior of the differential cross sections can be understood in terms of the semiclassical decomposition of Brink and Takigawa. A natural extrapolation of the global potential below 30 MeV is shown to reproduce the wide bump observed in the experimental excitation functions around 20 MeV. This bump is shown to be due to an l=8 shape resonance and is interpreted as the J=8+ member of the K=04+ rotational band of Ne20, in contradiction with the current attribution. Other bound and quasibound states supported by the potential are discussed in the light of orthogonality condition model-type arguments and shown to be consistent with the well-known K=01+ and 0- bands, and with the first three states of the K=04+ band of Ne20. NUCLEAR REACTIONS O16(,), measured (), E=39.3, 49.5, 69.5 MeV; global optical model analysis, E=32-146 MeV; semiclassical decomposition of the scattering amplitude; investigation of the compatibility of the potential description with existing low energy data and comparison with cluster models. © 1983 The American Physical Society.