J.T. Rhee

Multiplicities and rapidity densities in 200 A GeV 16O interactions with emulsion nuclei

Abstract We report on an experiment in which emulsion chambers were exposed to a beam of 200 A GeV 16 O at the CERN SPS. Pseudo-rapidity distributions are measured with high precision. Pseudo-rapidity densities of 140 particles per unit rapidity corresponding to an energy density of about 3 GeV/fm3 are observed. Pseudo-rapidity density distributions and fluctuations are found to satisfactorily agree with the Lund Monte Carlo model Fritiof, although new and unknown sources for fluctuations might still be present.

Target nucleus fragmentation in 16O+(Ag,Br) interactions at 200 A GeV

Abstract The multiplicity distributions of low-energetic target-associated particles from 200 A GeV oxygen-induced interactions with emulsion nuclei are presented. The experimental distributions are compared with distributions obtained using the Ranft and Fritiof simulation codes. It is found that the intra-nuclear cascade plays an important role in ion-induced interactions, similar to what is the case for hadron-induced interactions.

On the multiplicity fluctuations in relativistic heavy ion collisions

Abstract In the present letter we discuss the general features of the multiplicity distributions in relativistic heavy ion collisions. It is shown that from simple statistical considerations it is possible to predict the dependence of the dispersions of multiplicity distributions on the average multiplicities in any given rapidty wwindow. The applicability of the negative binomial distribution to multiplicity distributions from collisions with heavy ions is discussed.

ON THE ENERGY AND MASS DEPENDENCE OF THE MULTIPLICITY IN RELATIVISTIC HEAVY-ION INTERACTIONS

The average multiplicities of singly charged relativistic particles in oxygen-induced interactions with a nuclear emulsion target are studied over the energy range 2.1–200 A GeV. A similar energy dependence as for proton-induced interactions is observed. Both the number of participating nucleons and the number of binary collisions are shown to be of importance for the particle production.

A study of recoil protons in ultra-relativistic nucleus-nucleus collisions

Abstract An investigation of the energy dependence of grey prong producing particles in 16 O+ emulsion interactions at energies from 2.1 to 200 A GeV is reported. Many of the features of these particles, known from hadron-induced interactions, are shown to be of importance also in heavy-ion interactions, i.e. multiplicity and angular distributions as well as the impact parameter dependence are energy independent. Furthermore the angular distribution seems to be independent of the projectile and target masses as well as centrality of the interactions. Both the Fritiof and Ranft models fail to reproduce this general angular shape.

Study of double-strangeness nuclei with hybrid-emulsion method (KEK-PS E373)

Abstract An experiment to search for double-strangeness nuclei in nuclear emulsion is now being carried on as KEK-PS E373. Preliminary results of the data analysis for the K + spectrometer and the scintillating fiber detectors are presented. Status of the automatic track finding method for the emulsion is reported.

A systematic study of the energy independent behaviour of the fragmentation regions in16O-Em interactions from 3.7 to 200A GeV

The scaling behaviour in the fragmentation regions is investigated for16O-Em interactions from 3.7 to 200A GeV. It is found that in both the projectile- and the target-fragmentation regions, the multiplicity and pseudo-rapidity distributions as well as the two-particle pseudo-rapidity correlations are independent of incident energy. The intermittency indices at 14.6, 60 and 200A GeV are the same within the experimental errors, indicating that the limiting fragmentation hypothesis works with regard to dynamical as well as statistical fluctuations.

Multiplicities and rapidity densities in interactions with emulsion nuclei

Abstract We report on an experiment in which emulsion chambers were exposed to a beam of 200 A GeV 16 O at the CERN SPS. Pseudo-rapidity distributions are measured with high precision. Pseudo-rapidity densities of 140 particles per unit rapidity corresponding to an energy density of about 3 GeV/fm3 are observed. Pseudo-rapidity density distributions and fluctuations are found to satisfactorily agree with the Lund Monte Carlo model Fritiof, although new and unknown sources for fluctuations might still be present.

Pseudorapidity distributions and correlations in central 16O interactions at 200 A GeV

Here we present results on charged hadron production in an experiment using tracking detectors with the highest possible spatial resolution: emulsion chambers. A sample of the most central collisions will be compared to the predictions of the Lund Model, which does an accurate job of representing conventional (non−quark−gluon plasma) physics in nuclear reactions. We can use the high resolution of our detectors to examine spatial correlations in several ways. In particular, the radial size of the particle formation region can be estimated using pion interferometry techniques.  (AIP)