Antiproton production in relativistic heavy ion collisions

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7233173

Greene, S V

The E814 collaboration has made a systematic study of antiproton production in collisions of [sup 28]Si ions at 14.6 GeV per nucleon with targets of Pb, Cu, and Al. The E814 spectrometer consists of three tracking chambers for momentum measurement, a scintillator hodoscope to measure charge and time of flight, and a sampling calorimeter. The spectrometer accepts all particles produced within a rectangular aperture centered on the beam axis, with [delta][theta][sub x] = 37.6mr and [delta][theta][sub y] = 24.1mr. A trigger based on the flight time of particles through the spectrometer enhances selection of events which produce negatively charged particles having a rapidity within 0.5 units of the center of mass rapidity. Measurements of the antiproton yield per interaction and the invariant cross section for production at zero degrees are presented. The time-of-flight trigger allows for an unbiased measurement of the probability to produce antiprotons as a function of the impact parameter of the collision. Several measures of collision centrality are used. The energy produced transverse to the beam direction is measured with the target calorimeter, an array of NaI crystals surrounding the target assembly with a pseudorapidity coverage of [minus]0.5 < [eta] < 0.8. A second measurement of the event transverse energy is made using the participant calorimeter, a lead-scintillator sampling calorimeter sensitive to particles with pseudorapidities in the range 0.83 < [eta] < 3.9. Charged particle multiplicity is measured by a pair of annular silicon pad detectors over a pseudorapidity interval of 0.88 < [eta] < 3.9. The amount of energy produced in the collisions which travels in the beam direction is measured using a lead-uranium-scintillator sampling calorimeter. The antiproton yield per interaction is a function of centrality for each of the targets. These measurements are discussed in the context of initial production and subsequent annihilation of the antiprotons.

• Research Organization: Yale Univ., New Haven, CT (United States)
• OSTI ID: 7233173
• Country of Publication: United States
• Language: English

Related Subjects

663450* -- Heavy-Ion-Induced Reactions &amp; Scattering-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALUMINIUM
ANTIBARYONS
ANTIMATTER
ANTINUCLEI
ANTINUCLEONS
ANTIPARTICLES
ANTIPROTONS
ATOM COLLISIONS
BARYONS
CHARGED-PARTICLE REACTIONS
COLLISIONS
COPPER
CROSS SECTIONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY RANGE
EVEN-EVEN NUCLEI
FERMIONS
GEV RANGE
GEV RANGE 10-100
HADRONS
HEAVY ION REACTIONS
ION COLLISIONS
ION-ATOM COLLISIONS
ISOTOPES
LEAD
LIGHT NUCLEI
MATTER
METALS
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
RELATIVISTIC RANGE
SILICON 28
SILICON ISOTOPES
STABLE ISOTOPES
TRANSITION ELEMENTS