Lepton pairs from thermal mesons

Journal Article · Fri Apr 01 00:00:00 EST 1994 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.49.3338· OSTI ID:5016743

Gale, C ^[1]; Lichard, P ^[2]

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1. Physics Department, McGill University, 3600 University St., Montreal, Quebec, H3A 2T8 (Canada)
2. Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455 (United States) Department of Theoretical Physics, Faculty of Mathematics and Physics, Comenius University, CS-842 15 Bratislava, Slovakia ( )

We study the net dielectron production rates from an ensemble of thermal mesons, using an effective Lagrangian to model their interaction. The coupling between the electromagnetic and the hadronic sectors is done through the vector meson dominance approach. For the first time, a complete set of light mesons is considered. We include contributions from decays of the type [ital V]([ital P])[r arrow][ital P]([ital V])+[ital e][sup +][ital e[minus]], where [ital V] is a vector meson and [ital P] is a pseudoscalar, as well as those from binary reactions [ital P]+[ital P], [ital V]+[ital V], and [ital V]+[ital P][r arrow][ital e][sup +][ital e[minus]]. Direct decays of the type [ital V][r arrow][ital e][sup +][ital e[minus]] are included and shown to be important. We find that the dielectron invariant mass spectrum naturally divides in distinct regions: in the low mass domain the decays from vector and pseudoscalar mesons form the dominant contribution. The pion-pion annihilation and direct decays then pick up and form the leading signal in an invariant mass region that includes the [rho]-[omega] complex and extends up to the [phi]. Above the invariant mass [ital M][approx]1 GeV other two-body reactions take over as the prominent mechanisms for lepton pair generation. These facts will have a quantitative bearing on the eventual identification of the quark-gluon plasma.

• DOE Contract Number: FG02-87ER40328
• OSTI ID: 5016743
• Journal Information: Physical Review, D (Particles Fields); (United States), Vol. 49:7; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
LEPTONS
PAIR PRODUCTION
PSEUDOSCALAR MESONS
MASS SPECTRA
QUARK MATTER
VECTOR DOMINANCE MODEL
BOSONS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
INTERACTIONS
MATHEMATICAL MODELS
MATTER
MESONS
PARTICLE MODELS
PARTICLE PRODUCTION
SPECTRA
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662340 - Hadron Interactions- (1992-)