High Energy Proton-Emulsion Nucleus Interactions.
This paper presents the results of an experiment in which nuclear emulsions were exposed to the 800 GeV proton beam at Fermi National Accelerator Laboratory. This is the highest energy proton beam presently available for a fixed target experiment. This research provides a systematic, high statistics study of proton-nucleus interactions and yields new information on multiplicities, target fragmentation, and particle correlations. The results are used to evaluate theoretical particle production models. Extrapolations to nucleus-nucleus collisions are made on the basis of these models. Both single particle and two particle distributions have been analyzed. The multiplicity distribution of produced particles can be fit to either a KNO scaling function or a Negative Binomial Distribution. The dispersion, ratio of the dispersion to average multiplicity, and normalized particle multiplicity all follow the trend of lower energy data. Specific calculations of the forward/backward correlations, the two particle correlation function, and the pseudorapidity gap distributions have been compared to the theoretical predictions of different quark models and a collective model, as well as to proton-proton data and lower energy proton-emulsion data. Two different Monte Carlo calculations were performed, one assuming that particles are produced independently, the other assuming a cluster production. These substantiate the results, which support the idea of particle production in clusters with an average cluster size of approximately 3 particles. A large long range correlation, much greater than seen in proton-proton data, has been observed.
- Pub Date:
- Physics: Elementary Particles and High Energy