Direct electron pair production in. pi. /sup -/p interactions at 16 GeV/c and a model for direct lepton and photon production at low P/sub T/

Conference · Wed Jul 01 00:00:00 EDT 1981

OSTI ID:5931787

Blockus, D; Dunwoodie, W; Leith, D W.G.S.

The production of prompt electron-positron pairs in 16 GeV/c ..pi../sup -/p collisions has been measured using the LASS spectrometer at SLAC. An excess of events is observed above the estimated contributions of direct and Dalitz decay of known resonances in the kinematic range defined by 0.1 less than or equal to x less than or equal to 0.45, 0 less than or equal to P/sub T/ less than or equal to 0.8 GeV/c and 0.2 less than or equal to M(e/sup +/e/sup -/) less than or equal to 0.7 GeV/c/sup 2/. The excess signal decreases slowly with increasing M, but exhibits very steep x and P/sub T//sup 2/ dependence. The contribution of this signal to the e/sup +/e/sup -//..pi../sup +/..pi../sup -/ and ..gamma../..pi.. ratios is discussed. Detailed comparisons are made between e/sup +/e/sup -/ distributions and the corresponding low mass ..mu../sup +/..mu../sup -/ distributions, and a simple production mechanism is proposed which describes the 16 GeV/c data well. The implications for direct photon production are presented, and it is shown that the model provides simultaneously a good description of the experimental data on the (e/..pi..) and (..mu../..pi..) ratios for p/sub T/ < 1 GeV/c.

• Research Organization: Stanford Linear Accelerator Center, CA (USA); Johns Hopkins Medical Institutions, Baltimore, MD (USA); California Inst. of Tech., Pasadena (USA)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 5931787
• Report Number(s): SLAC-PUB-2770; CONF-810895-2; ON: DE82003568; TRN: 82-001174
• Resource Relation: Conference: International symposium on lepton and photon interactions at high energies, Bonn, F.R. Germany, 24 Aug 1981
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ELECTRON PAIRS
PAIR PRODUCTION
MUON PAIRS
PION MINUS-PROTON INTERACTIONS
CROSS SECTIONS
ELECTRONS
EXPERIMENTAL DATA
GEV RANGE 10-100
INCLUSIVE INTERACTIONS
MASS SPECTRA
MUONS MINUS
MUONS PLUS
PHOTONS
PIONS MINUS
PIONS PLUS
POSITRONS
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BOSONS
DATA
ELEMENTARY PARTICLES
ENERGY RANGE
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HADRON-HADRON INTERACTIONS
HADRONS
INFORMATION
INTERACTIONS
LEPTONS
MASSLESS PARTICLES
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
MESONS
MUONS
NUMERICAL DATA
PARTICLE INTERACTIONS
PION-NUCLEON INTERACTIONS
PION-PROTON INTERACTIONS
PIONS
PSEUDOSCALAR MESONS
SPECTRA
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