The pion mass difference in threshold pion reactions on light nuclei

We investigate the effect of the pion mass difference in scattering and photoproduction of pions on light nuclei near threshold. The effect is found to be most easily described in a nuclear K-matrix formalism where the nuclear K-matrix elements are shown to be independent of the mass difference.     

Fluorine NMR studies of solid SiF4

Fluorine NMR second moments and spin-lattice relaxation times were measured for solid SiF₄. The results indicate a hindered molecular motion and piezoelectricity in solid SiF₄.     

Landau parameters for nuclear matter using the Skyrme interaction

Landau parameters for nuclear matter are calculated for several Skyrme interactions. Resulting values of G_o and G′_o are in disgreement with empirical values and lead to instability against spin collapse in several cases. A suitable generalization of the interaction is suggested to overcome these difficulties.     

Rapidity density distributions in antiproton-proton collisions

Data on the density of charged particles in rapidity space for annihilation and non-annihilation p?p interactions at 7.3 and 12 GeV/c are reported. It is shown that the central rapidity density for non-annihilation processes is a simple linear function of $\text{ln}\text{(}\text{s}\text{)}$ from these low energies up to p?p collider energies ($\text{s}\text{=540}\text{GeV}$). Significant differences in density distributions for p?p and e^?e⁺ annihilations at comparable energies are found.     

Study of Wigner's theorem on joint probabilities

The exact bearing of an important theorem proved by Wigner is established. The study brings out the fact that marginal conditions as well as mean conditions of a form currently required in joint probability attempts are in fact inadequate for the determination of a relevant concept of a joint probability. New vistas are thereby opened up.     

Konjugierte Teilkörper eines Körpers

Ohne Zusammenfassung     

Screening of charge in a semiinfinite electron gas

Within linear response and the self-consistent field approximation an equation for the screening of a chargee ^iwt δ(r?r ₀),r ₀=(0, 0,z ₀) by an electrongas confined to the half-spacez>0 is derived. From this 3 cases are discussed: 1. Application to a homogeneous electron gas bounded by an infinite potential. 2. Thomas-Fermi approximation. 3. Image potential approximation.     

Nuclear polarized7Li and14N ions via ion beam surface interaction at grazing incidence

Using singly or doubly reflected 270keV-ions from a Cu-surface at grazing incidence nuclear polarizations in⁷Li ofP _I=(6.8±0.6) % orP _I= (11.5±1.0) % and in¹⁴N ofP _I =(14.8±1.0) % orP _I=(20.0±1.0) % respectively, have been achieved.     

Frontier orbital controlled cycloaddition of 2-azapentalenes

It is shown that cycloadditions of 1,3-bis (dimethylamino) pentalenes and their 2-aza-analogues with activated alkines are frontier orbital controlled whereas protonation is charge controlled.