abstract

The frequency dependence of component separation in pulsar integrated profiles is considered. A development of Komesaroff’s hypothesis concerning this problem is presented. Komesaroff (1970) obtained the \(\nu ^{-1/3}\) dependence by using very peculiar assumptions: (i) the magnetic axis passes through the observer, and (ii) the component peak at different frequencies is produced along the same dipole field line. It is shown that a generalization of these assumptions permits one to obtain different values of the separation index, according to the angle between the line-of-sight and the magnetic axis.

abstract

Either partons arc responsible for particle production in soft hadronic reactions or we shall have to reconsider deep inelastic lepton–hadron and e\(^+\)e\(^-\) collisions. This is shown in a comparison of data on soft hadron–hadron collisions to each other and to deep inelastic lepton–hadron and e\(^+\)e\(^-\) collisions in the light of quark–parton pictures. Three basic observations can be made. They are the success of quark combinatorics to explain hadron yields. of various quantum numbers, the reflection of the valence quark structure function in hadronic pion production, and the similarity of jets in hadron–hadron, deep inelastic lepton–hadron and e\(^+\)e\(^-\) collisions.The models evolving from these observations help to illuminate various aspects of the data. Quark and diquark fragmentation functions extracted from hadron–hadron collisions agree with those from neutrino–hadron collisions. Kaon and pion structure functions agree with those obtained from muon-pair production. Hyperon polarization at large energies, not understandable from reggeology, follows naturally from quark-fragmentation-recombination. While a new field has silently evolved in these observations. over the last years, the field will have to gain in depth. In a second approximation, deviations from similarity will have to be shown to exist where expected.

abstract

After a brief review of the main features of the gauge theory of weak interactions, known as SU(2)\(_{\rm L}\times \) U(1), the up-to-date experimental situation is presented. In the charged current sector the \(\mu ^+\) polarization measurement from the reaction \(\bar \nu _{\mu }{\rm N}\to \mu ^+\)X gives a general confirwation at large \(Q^2\) of the gauge nature of the weak interaction. The neutral current weak interaction results from e\(^+\)e\(^-\) storage rings and in neutrino quark scattering are reviewed with particular attention to the measurement of the weak strength parameter \(\sin ^2\theta _{\rm W}\).

abstract

In these lectures I will describe our group’s recent experiments performed in the Meson Area of Fermilab. I will begin with a discussion of the theoretical motivation for the investigation of the interactions of mesons in the nuclear Coulomb field, describe the apparatus used in the studies and the results obtained thus far, then I will proceed to a brief description of the physics of direct-photon production in hadronic reactions and, finally, to cur tests of the feasibility of using a liquid-argon detector for studying such processes at Tevatron energies.

abstract

The properties of asymmetric nuclear matter are studied using several existing parametrizations of the Skyrme interaction. The dependence of the Fermi liquid parameters and of the compression modulus on the neutron excess is investigated. Apart from the standard case of nuclear matter at zero pressure, the case of highly asymmetric nuclear matter under high pressure, relevant to astrophysical applications, is also studied.