abstract

The physical role of zero-point oscillations and zero-point energies in relativistic local quantum field theory is discussed. A mathematically rigorous distribution-theoretic approach to free fields and their divergent zero-point stress integrals is formulated. A chronic malady of Lorentz non-invariance on the part of the vacuum stress is diagnosed and cured, leading to a privileged family of free-field systems for which the vacuum stresses are already finite and relativistic, without need for subtractions. Building upon this, a heuristic principle is introduced for interacting fields. The principle asserts that the zero-point energy should change only finitely under external perturbations. Its implementation leads to an ultraviolet convergence condition, which expresses many relations between masses and coupling constants through a single formula. The propagators and vacuum bubbles of two-dimensional theories obeying the formula are entirely finite, wholly unambiguous, and unitary; in dimensions higher than two the divergences are softened. Global supersymmetry appears as a special mass-degenerate case, and further convergence conditions appropriate to three and four dimensions can be foreseen.

abstract

In a bubble chamber experiment with BEBC filled with hydrogen at the CERN SPS the hadronic final state in neutrino-proton scattering has been studied by the Aachen-Bonn-CERN-München(MPI)-Oxford Collaboration. Results are presented on the following topics: charged multiplicity distribution, forward and backward multiplicities and charge distribution, production of neutral strange particles and of charm, quark-singlet and gluon fragmentation moments, non-factorisation and double moments, transverse momentum and jet studies.

abstract

We analyze high energy behaviour of multi-gluon exchange amplitudes in the leading-ln \(s\) approximation in perturbation theory. Working in the Coulomb gauge and employing Ward identities we derive an integral equation for the \(n\)-gluon system in the exchange channel. We find that the Regge behaviour is associated with exponentiation of leading infrared divergences, and the position of the \(j\)-plane singularities is determined by the colour quantum numbers of the exchanged system.

abstract

Grabińska and Zabierowski’s (1980) alleged new large dimensionless numbers are shown to be formally identical to Dirac’s original large numbers, if one uses for the Hagedorn maximal universal temperature its expression derived in the framework of Hagedorn’s statistical thermodynamics of strong interactions.