Particle production in nucleon-nucleus and nucleus-nucleus collisions: Fermi motion versus collective tube mechanisms

Journal Article · Wed Aug 01 00:00:00 EDT 1979 · Phys. Rev., C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.20.715· OSTI ID:6089366

Vary, J P; Lassila, K E; Sandel, M S

Within the general framework of multiple scattering theory for particle production in nucleon-nucleus and nucleus-nucleus collisions we investigate the results of two limiting situations: independent multiple collisions with Fermi motion effects versus the collective tube model with the assumption of universality for the elementary cross sections. Dramatically different predictions may be obtained. We summarize the results for pion multiplicity distributions in nucleus-nucleus collisions to assess the possible evidence for a coherent-collective mechanism and find that no strong conclusion is possible with the currently available pion multiplicity data. Attention is then focused on potentially more conclusive tests: subthreshold (in the nucleon-nucleon kinematics) production of massive particles, p-bar, psi/J, and W as examples. Evidence for a collective mechanism is found by examining subthreshold p-bar production data in particle-nucleus collisions. However, owing to the limited scope of these data a firm conclusion is probably premature. Further p-bar production experiments are proposed. With the assumption that the coherent mechanism can be proved, it is worth studying the possibility of producing other massive particles, especially in nucleus-nucleus collisions where the collective effects have large subthreshold consequences. Within the (limited) framework of universality we then present predictions for the subthreshold production of psi/J and the W boson. Owing to the qualitative nature of our assumptions and since these approaches bracket the p-bar data, we expect that the collective tube model provides an optimistic limit and independent multiple collisions a pessimistic limit for W production cross sections.

• Research Organization: Lawrence Berkeley Laboratory, Berkeley, California 94720
• OSTI ID: 6089366
• Journal Information: Phys. Rev., C; (United States), Journal Name: Phys. Rev., C; (United States) Vol. 20:2; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

653003* -- Nuclear Theory-- Nuclear Reactions & Scattering
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
AMPLITUDES
ANTIBARYONS
ANTIMATTER
ANTINUCLEI
ANTINUCLEONS
ANTIPARTICLES
ANTIPROTONS
BARYON REACTIONS
BARYONS
BOSONS
CHARGED-PARTICLE REACTIONS
COLLECTIVE MODEL
CROSS SECTIONS
ELEMENTARY PARTICLES
FERMI STATISTICS
FERMIONS
HADRON REACTIONS
HADRONS
HEAVY ION REACTIONS
INTERACTIONS
INTERMEDIATE BOSONS
KINETICS
MATHEMATICAL MODELS
MESON RESONANCES
MESONS
MULTIPLE SCATTERING
MULTIPLICITY
NUCLEAR MODELS
NUCLEAR REACTION KINETICS
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PIONS
POSTULATED PARTICLES
PSEUDOSCALAR MESONS
PSI RESONANCES
REACTION KINETICS
RESONANCE PARTICLES
SCATTERING
SCATTERING AMPLITUDES
VECTOR MESONS