Contribution of two-pion annihilation to dilepton emission from proton-nucleon collisions

Journal Article · Sun Oct 01 04:00:00 EDT 1989 · Physical Review (Section) C: Nuclear Physics; (USA)

DOI:https://doi.org/10.1103/PhysRevC.40.R1574· OSTI ID:5461595

Kapusta, J ^[1]; Lichard, P ^[2]

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1. School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (US)
2. Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455

The Dilepton Spectrometer collaboration has reported a bump in the {ital e}{sup +}{ital e}{sup {minus}} mass distribution at around 2{ital m}{sub {pi}} in 4.9 GeV proton-Be collisions. Previous calculations have shown that this bump does not have its origin in nucleon-nucleon bremsstrahlung nor in the Dalitz decay of the {Delta} resonance. In this paper we estimate the contribution from two-pion annihilation based on relativistic kinetic theory, on the experimentally measured cross sections for the production of up to five pions, and on a phase space generator for the pion momentum distributions. The calculation fails to reproduce the data.. The origin of the bump remains unexplained.

• OSTI ID: 5461595
• Journal Information: Physical Review (Section) C: Nuclear Physics; (USA), Journal Name: Physical Review (Section) C: Nuclear Physics; (USA) Vol. 40:4; ISSN 0556-2813; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

645204* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Strong Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANNIHILATION
BARYON REACTIONS
BARYON-BARYON INTERACTIONS
BASIC INTERACTIONS
BERYLLIUM 9 TARGET
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
ELECTROMAGNETIC INTERACTIONS
ELECTRON PAIRS
ENERGY RANGE
GEV RANGE
GEV RANGE 01-10
HADRON REACTIONS
HADRON-HADRON INTERACTIONS
INTERACTIONS
MATHEMATICAL SPACE
MESON-MESON INTERACTIONS
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUCLEON-NUCLEON INTERACTIONS
PAIR PRODUCTION
PARTICLE INTERACTIONS
PARTICLE KINEMATICS
PHASE SPACE
PION-PION INTERACTIONS
PROTON REACTIONS
PROTON-NUCLEON INTERACTIONS
PROTON-PROTON INTERACTIONS
SPACE
TARGETS
WIGNER DISTRIBUTION