Investigation of rare particle production in relativistic heavy ion collisions
During FY91 we began our investigation of rare particle production in relativistic nuclear collisions at the Brookhaven National Laboratory. We were funded for a period of one year to perform the initial experimental search, E858, to determine the level of antideuteron ({bar d}) production in Si+Au collisions at the AGS. We accomplished this goal with the discovery of two {bar d}'s in the June 1990 run. We describe in this paper experiment performed and the results obtained. We performed our rare particle search at the A-1 line of the AGS. We instrumented the line with a four time-of-flight (TOF) detectors, two high pressure gas Cerenkox (ck) detectors, and four drift tube (DT) tracking detectors. The TOF detectors achieved time resolution of better than 100ps leading to a mass resolution of <15 MeV at 1 GeV. The Ck detectors were used both to suppress the large {pi}{sup {minus}} signal and in {pi}/K separation at high rigidities. The DT system provided particle trajectories for all of the particles passing the trigger requirements. In this experiment we measured the {pi}{sup {minus}}, K-, and {bar p} momentum spectra at 0{sup o} for rigidities from 2 to 8 GV to a statistical accuracy of 1--3% at all settings. We found that the {bar p} yield as a function of target did not show any evidence for reabsorption within the interaction volume. We also found two {bar d}'s, the first observation of complex antinuclei produced in nucleus-nucleus collisions. The {bar d} yield is at least an order of magnitude smaller than prediced using a simple coalescence model based on the d/p ratio from E802 and the {bar p} spectrum measured in our experiment.
- Research Organization:
- Univ. of California, Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG03-90ER40571
- OSTI ID:
- 6384495
- Report Number(s):
- DOE/ER/40571-1; ON: DE92003434; TRN: 91-033290
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANTIDEUTERONS
PARTICLE PRODUCTION
HEAVY ION REACTIONS
GOLD 197 TARGET
PROGRESS REPORT
RELATIVISTIC RANGE
SILICON 28 REACTIONS
TIME-OF-FLIGHT SPECTROMETERS
ANTIMATTER
ANTINUCLEI
ANTIPARTICLES
CHARGED-PARTICLE REACTIONS
DOCUMENT TYPES
ELEMENTARY PARTICLES
ENERGY RANGE
MATTER
MEASURING INSTRUMENTS
NUCLEAR REACTIONS
NUCLEI
SPECTROMETERS
TARGETS
663450* - Heavy-Ion-Induced Reactions & Scattering- (1992-)
662340 - Hadron Interactions- (1992-)