Per Osland

Polarization in elastic proton-nucleus scattering

Abstract The polarizations which result from the elastic scattering of protons by spin-zero nuclei are discussed by means of the multiple-diffraction approximation. They are found to depend largely on the elementary proton-nucleon central-force and spin-orbit scattering amplitudes and, at least for heavy nuclei, to depend very little upon the remaining proton-nucleon amplitudes which are proportional to the spins of the target nucleons. In particular, the values of the polarization measured at small angles can be used to determine the imaginary part of the forward proton-nucleon spin-orbit scattering amplitude. The real part of that amplitude, on the other hand, is much less sensitively determined by the polarization distributions. Its evaluation will probably require more detailed measurements on the proton spin distribution. We show that the effects of the Coulomb field on the polarization distributions are significant at all scattering angles. Included among these electromagnetic effects is the relativistic interaction of the proton magnetic moment with the Coulomb field.

Gluon bremsstrahlung in e+e- annihilation: (I). Neutral current and beam polarization effects

The cross section for gluon bremsstrahlung, e+e− → qqg, is calculated for the case of arbitrarily polarized electron-position beams, including weak interaction effects, in the Glashow-Weinberg-Salam model. The weak neutral current effects somewhat reduce the dependence of the cross section on transverse beam polarization, and lead to a rotation of the azimuthal distributions, as compared with the low-energy limit. This leads to flavour separation, in the sense that the azimuthal distributions are different for up and down quark flavours.

High-energy, large-momentum-transfer processes: Ladder diagrams in ϕ3 theory (II)

Abstract Relativistic quantum field theories may give us useful guidance to understanding high-energy, large-momentum-transfer processes, where the center-of-mass energy is much larger than the transverse momentum transfers, which are in turn much larger than the masses of the participating particles. With this possibility in mind, we study the ladder diagrams in ϕ 3 theory. In this paper, some of the necessary techniques are developed and applied to the simplest cases of the fourth- and sixth-order ladder diagrams.

Spin-rotation effects in elastic proton-nucleus scattering

Abstract We discuss a particular form of spin-rotation distribution in the context of proton-nuclear scattering and indicate its behaviour as a function of momentum transfer. We point out that besides effectively completing our knowledge of the nuclear scattering amplitudes the measurement of this function would furnish information both about the nuclear density distribution and about parts of the fundamental proton-nucleon spin-orbit scattering amplitudes. The latter are terms of the amplitudes which have been left undetermined by existing polarization data.

KAZAMA-YANG MONOPOLE - FERMION BOUND STATES. 1. ANALYTIC RESULTS

Abstract We present explicit, approximate, remarkably precise results for the Kazama-Yang monopole-fermion binding energies and wave functions. The results are valid for the states of lowest angular momentum and for the binding energy M − E ⪡ M . They agree very well with the numerically calculated values.

Spin effects in inelastic proton-nucleus scattering

Abstract We include the spin-orbit force in the analysis of inelastic proton-nucleus scattering. In the limit of zero-range nuclear forces, very simple results are obtained. To lowest order in the elementary spin-orbit amplitude, the spin-dependent nuclear amplitudes are proportional to the momentum transfer times the spin-independent nuclear amplitudes. Consequently, in the spin-independent cross section the region of the diffractive minima is not significantly affected by the elementary spinorbit amplitudes, whereas the subsidiary maxima are somewhat enhanced.

Noneikonal effects in spin-dependent proton-nucleus interactions☆

Abstract Simple expressions are derived for the non-eikonal corrections to the Glauber diffraction approximation for the proton-nucleus scattering amplitudes, with the spin dependence of the proton-nucleon amplitudes taken into account. As an example, we study the numerical importance of these corrections for elastic p 58 Ni scattering at 800 MeV.

Polarized gluon bremsstrahlung as a test of QCD

Abstract Gluon bremsstrahlung emitted in electron-positron annihilation at high energies is found to have a remarkably high degree of linear polarization. It is suggested that measurements of the gluon polarization through angular correlations in the decay of isoscalar vector mesons or possibly through gluon jet oblateness could constitute sensitive test of QCD.

Gluino pair production in electron-positron annihilation

Abstract We summarize the effects of some unknown supersymmetry breaking mechanism by the addition to the super-QCD lagrangian of explicit, and different, mass terms for the scalar superpartners of quarks and antiquarks. Allowing also a possible Majorana mass for the gluino, we then calculate cross sections for e + e − → two gluinos, a process which may be observable if the gluino is sufficiently long-lived.

Flavour separation by means of transverse beam polarization in high-energy e+e- annihilation

Abstract Transverse beam polarization is in e + e - annihilation at high energies shown to lead to a strong azimuthal variation in the flavour composition of the produced quark-antiquark pairs. We describe, in the SU(2) × U(1) model, a way in which this could be used to obtain flavour-specific information on the quark fragmentation functions. In inclusive charged particle rates the effect might be much reduced, but still observable.