PARTICLE PRODUCTION AT COLLIDER ENERGIES

Abstract

High energy particle physics, which has been trying to understand and to devise new laws governing nature at per particle energies far beyond everyday energies, has entered a new episode. Having surpassed the ‘low energy’ regime, where (s channel) resonance production dominantly projects onto the final state, very interesting features of the strong interaction arose at c.m. energies in the tens of GEV range, as found at the CERN Intersecting Storage Rings (ISR). One recalls the onset of hard scattering processes, which was understood as a scattering between constituents of the nucleon, hence supporting the Quark Parton Model (QPM). Surprisingly enough the total cross section started to rise again, when it was initially believed to have reached a constant value, suggesting an asymptotia. Furthermore correlations among the final state particles produced were observed, and especially long range correlations, which must reflect dynamical laws. The advent of the CERN [Formula: see text] Collider, with c.m. energies up to 900 GeV, representing a step of more than an order of magnitude in the energy available, puts one into a position to test more directly many of these ‘new’ things and to prove the existence of the elusive intermediate vector bosons W± and Z, thus unifying weak and electromagnetic interactions. Finally a bridge to cosmic ray results at extreme energies may be provided. Naturally quite a lot of new unanswered questions will emerge in the investigations of Collider data, since new regions bring new surprises, but this possibility should be regarded as a means of gaining new insights, rather than as a disturbance of hitherto believed regularities, of which some inevitably fail. In this spirit the following article is written.