Y. Pang

Strange cluster formation in relativistic heavy ion collisions

Using the cascade code ARC to simulate relativistic heavy ion collisions at Brookhaven AGS energies (11.7--14.6 GeV/c), the authors have estimated the production rate of strange clusters ranging from a hypothetical doubly strange (S={minus}2) bound ({Lambda}{Lambda}){sub b} dibaryon to the hypernuclei {sub {Lambda}{Lambda}}{sup 6}He and {sub {Xi}{sup 0}{Lambda}{Lambda}}{sup 7}He. For the formation of multi-strange bound systems, high energy heavy ion collisions offer the only feasible method, since one can take advantage of the hyperons which are copiously produced in such collisions (typically 20 {Lambda}`s in a Au + Au central collision at the AGS) to form the composite object by coalescence.

ARC — A relativistic cascade

Abstract A general purpose relativistic cascade code ARC has been developed to study ion-ion collisions. As a first application of ARC we study Si+Au collisions at 14.6 GeV/ c using two hadronic models which use the same two-body data as input, but with different assumptions about the way particles are produced. Comparison with data from experiment E802 suggests the importance of baryonic resonances in nucleus-nucleus collisions at BNL-AGS energies.

P ANNIHILATION IN AU + AU AT 11 GEV/C. AUTHORS' REPLY

Antinucleon production in heavy ion collisions is potentially an excellent signal for unusual phenomena in hot and dense matter. However, at the low energies available at the AGS the annihilation process must be handled with care. In this Comment, we consider the case of Au + Au collisions at approximately 11 GeV/c, applying the ARC treatment of pbar production and annihilation to the analysis of experiment E878. It is apparent that classical screening introduced for Si + Au is crucial in the understanding of data obtained with the more massive projectile. Unfortunately, there seems no necessity for invoking unusual behaviour in the Au + Au system.

A relativistic cascade for heavy ion collisions

Au on Au collisions at the BNL/AGS (11.6 GeV‐A/c) are expected to produce a short lived state of matter at high baryon density. If the baryons reach sufficiently high density, they may produce a quark‐gluon plasma (QGP). The signals from a QGP phase may be difficult to distinguish from those of ordinary hadronic matter. We have constructed a relativistic cascade (ARC) for hadrons in an attempt to model the dynamics of ordinary hadronic matter in a heavy ion collision, in the hopes that deviations from the cascade results may indicate new physics. In this contribution I will discuss the formation of high baryon density matter, and its effect on antiproton production.

{ovr {ital p}} Annihilation in Au+Au at 11GeV/{ital c}

Antinucleon production in heavy ion collisions is potentially an excellent signal for unusual phenomena in hot and dense matter. However, at the low energies available at the AGS the annihilation process must be handled with care. In this Comment, we consider the case of Au + Au collisions at approximately 11 GeV/c, applying the ARC treatment of pbar production and annihilation to the analysis of experiment E878. It is apparent that classical screening introduced for Si + Au is crucial in the understanding of data obtained with the more massive projectile. Unfortunately, there seems no necessity for invoking unusual behaviour in the Au + Au system.

Pbar Annihilation in Au+Au at AGS Energies

Antinucleon production in heavy ion collisions is potentially an excellent signal for unusual phenomena in hot and dense matter. However, at the low energies available at the AGS the annihilation process must be handled with care. In this Comment, we consider the case of Au + Au collisions at approximately 11 GeV/c, applying the ARC treatment of pbar production and annihilation to the analysis of experiment E878. It is apparent that classical screening introduced for Si + Au is crucial in the understanding of data obtained with the more massive projectile. Unfortunately, there seems no necessity for invoking unusual behaviour in the Au + Au system.

Strangeness from hadronic processes

Large amounts of experimental data on strangeness production in nucleon‐nucleon and in pion‐nucleon collisions, and data on hadronic scattering of strange particles, make it possible to calculate, with accuracy, the hadronic contribution to the strangeness production in nucleus‐nucleus reactions. The relativistic cascade model ARC, relying on the experimental measurements of elementary hadron‐hadron interactions, successfully predicted many single particle spectra in Au+Au collisions at BNL‐AGS, including those of strange mesons K±.