abstract

The relativistic radial equations for two spin 1/2 particles interacting via an instantaneous potential are derived. These equations are solved for the case of positronium. The solution obtained is similar to that of Schrodinger’s equation for a hydrogen like atom in the ground state.

abstract

We point out that according to multiple scattering models an antiproton incident on a heavy nucleus is likely to annihilate, even at incident momenta of a few hundreds GeV/\(c\), when the annihilation probability in \(\bar {\rm p}\)p collisions is very small. Experimentally, a comparison of the leading p and leading \(\bar {\rm p}\) spectra in pA and \(\bar {\rm p}\)A collisions at the same energy gives a good chance of discovering this effect, if it exists. Quantitative predictions valid for a wide class of multiple scattering models are presented and discussed.

abstract

We discuss further the recently proposed “primordial” quantum chromodynamics, where a massive Fermi–Bose couple of two colour triplets \(\delta \) and \(\chi \) of spin 1/2 and 0, respectively, and of equal charge \(-1/3\) inteiacts with a colour octet of massless vector gluons. The “preons” \(\delta \) and \(\chi \) form bound states \(v_{\rm e} = \delta \bar \chi \), e = \(\delta (\chi \chi )_{\rm P}\) (colour singlets) and u = \(\bar \delta \bar \chi \), d = \(\bar \delta (\chi \chi )_{\rm P}\) (colour triplets). Other preon bound states also exist and are briefly reviewed.

abstract

The Woods–Saxon (WS) and the squared Woods–Saxon (WS)\(^2\) parametrisations for the single and double folding potentials were tested. We showed that the (WS)\(^2\) form is appropriate for single as well as double folding approaches.

abstract

The influence of deformation on the Coulomb displacement energy for the nuclei of rare earth elements is considered. The essential contributions which change with deformation were calculated exactly using the shell model. The results were compared with experimental data.

abstract

The new \(^{160}\)Lu (\(T_{1/2}=34.5\pm 1.5\) sec), \(^{161}\)Lu (\(T_{1/2}=72\pm 6\) sec), \(^{163}\)Lu (\(T_{1/2}=4.1\pm 0.2\) min) have been identified as products of spallation reaction of tungsten by 1 GeV protons, using on-line mass-separator “IRIS”. The earlier identification of \(^{162}\)Lu isotope, having \(T_{1/2}=86\pm 5\) sec, has been confirmed. The identification for all four isotopes is based on the analysis of X- and \(\gamma \)-ray spectra, of mass separated samples. Single \(\gamma \)-spectra were measured. Energies and intensities of \(\gamma \)-transitions have been determined. Preliminary decay schemes are proposed.

abstract

New relations \(N_5 \approx 10^{40}\) and \(N_6\approx (10^{40})^2\) are in excellent agreement with Dirac’s theory predictions \(G \sim t^{-1}\) and \(N_3 \sim t^2\).

abstract

It is shown that the difference in nuclear attenuation of different hadrons produced in deep inelastic scattering of leptons from nuclear targets is sensitive to the composition of the intermediate state in nuclear matter. Measurements of attenuation should not only allow to determine if the high-energy component of this state is a quark or a hadron, but also give information on quark absorption cross-section and on time scale of hadronization.

abstract

Analytic solutions for the jet fragmentation functions in the leading log approximation for \(x\) close to 1 are found and compared with exact numerical results.