abstract

We review the predictions of Quantum Chromodynamics for the inclusive production of two hadrons in electron-positron annihilation at high energy in the “back-to-back” region. This cross section is sensitive to gluon bremsstrahlung effects. We discuss, in particular, the energy–energy correlation function and the two particle correlation function using higher moments in the particle energies. New results for the higher moments and for higher twist effects in the energy–energy correlation function are reported.

abstract

Relation between the weak mixing angles, the Kobayashi–Maskawa phase and the masses of pseudoscalar mesons are derived in a model with hierarchical symmetry breaking. A relation between \(\theta _3\) and \(\theta _1\) is found. Limits on \(\theta _2\) are also given. It is shown that sign \((\cos \delta ) = -{\rm sign} (\tan \theta _2)\). Flavor nonconservation at intermediate stages of hierarchical symmetry breaking leads to CP-breaking terms in the Hamiltonian density of the Gell–Mann, Oakes and Renner (GMOR) model.

abstract

The theoretical values of the moments of inertia and Coriolis decoupling parameters are obtained for the odd-\(A\) rare-earth nuclei in the ground and the one-quasiparticle excited states. Both these parameters are evaluated within the cranking model and in the adiabatic approximation. The quadrupolly and hexadecapolly deformed Nilsson potential is used. The BCS approximation for the pairing forces is applied.

abstract

A simple expression for the nuclear absorptive potential \(W\) in nuclear matter in terms of free \(NN\) cross section is derived from the Brueckner theory and tested against “exact” results. It is a modification of the semiclassical expression, which takes into account the Pauli blocking and dispersive effects. It is used to calculate \(W\) and the nucleon mean free path \(\lambda \) in nuclear matter for nucleon energies up to \(\sim 200\) MeV. Results obtained with non-locality corrections agree reasonably well with experiment. The dependence of \(W\) and \(\lambda \) on the temperature of nuclear matter is also discussed.