Dielectron production in Ar + KCl collisions at 1.76A GeV

Journal Article · Fri Jul 15 00:00:00 EDT 2011 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.84.014902· OSTI ID:21596599

Agakishiev, G; Belyaev, A; Chernenko, S; Fateev, O; Zanevsky, Y ^[1]; Balanda, A; Dybczak, A; Michalska, B; Otwinowski, J; Przygoda, W; Salabura, P; Trebacz, R; Wisniowski, M ^[2]; Belver, D; Cabanelas, P; Castro, E; Garzon, J A ^[3]; Blanco, A; Fonte, P; Lopes, L ^[4]

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1. Joint Institute of Nuclear Research, RU-141980 Dubna (Russian Federation)
2. Smoluchowski Institute of Physics, Jagiellonian University of Cracow, PL-30-059 Krakow (Poland)
3. Departamento de Fisica de Particulas, Univ. de Santiago de Compostela, E-15706 Santiago de Compostela (Spain)
4. LIP-Laboratorio de Instrumentacao e Fisica Experimental de Particulas, P-3004-516 Coimbra (Portugal)

We present results on dielectron production in {sup 40}Ar+KCl collisions at 1.76A GeV. For the first time {omega} mesons could be reconstructed in a heavy-ion reaction at a bombarding energy which is well below the production threshold in free nucleon-nucleon collisions. The {omega} multiplicity has been extracted and compared to the yields of other particles, in particular of the {phi} meson. At intermediate e{sup +}e{sup -} invariant masses, we find a strong enhancement of the pair yield over a reference spectrum from elementary nucleon-nucleon reactions, suggesting the onset of nontrivial effects of the nuclear medium. Transverse-mass spectra and angular distributions have been reconstructed in three invariant mass bins. In the former unexpectedly large slopes are found for high-mass pairs. The latter, in particular the helicity-angle distributions, are largely consistent with expectations for a pair cocktail dominated at intermediate masses by {Delta} Dalitz decays.

• OSTI ID: 21596599
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 84, Issue 1; Other Information: DOI: 10.1103/PhysRevC.84.014902; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
ARGON 40
ATOM-MOLECULE COLLISIONS
COLLISIONS
DALITZ PLOT
ELECTRONS
GEV RANGE 01-10
HEAVY ION REACTIONS
HELICITY
MASS
MASS SPECTRA
MESONS
MULTIPLICITY
NUCLEAR DECAY
NUCLEON REACTIONS
NUCLEON-NUCLEON INTERACTIONS
NUCLEONS
POSITRONS
POTASSIUM CHLORIDES
ALKALI METAL COMPOUNDS
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
ARGON ISOTOPES
ATOM COLLISIONS
BARYON REACTIONS
BARYON-BARYON INTERACTIONS
BARYONS
BOSONS
CHLORIDES
CHLORINE COMPOUNDS
DECAY
DIAGRAMS
DISTRIBUTION
ELEMENTARY PARTICLES
ENERGY RANGE
EVEN-EVEN NUCLEI
FERMIONS
GEV RANGE
HADRON REACTIONS
HADRON-HADRON INTERACTIONS
HADRONS
HALIDES
HALOGEN COMPOUNDS
INFORMATION
INTERACTIONS
ISOTOPES
LEPTONS
LIGHT NUCLEI
MATTER
MOLECULE COLLISIONS
NUCLEAR REACTIONS
NUCLEI
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
POTASSIUM COMPOUNDS
SCATTERPLOTS
SPECTRA
STABLE ISOTOPES