Search for long-lived neutral resonances in Bhabha scattering around 1. 8 MeV/ c sup 2

Journal Article · Mon Aug 20 04:00:00 EDT 1990 · Physical Review Letters; (USA)

DOI:https://doi.org/10.1103/PhysRevLett.65.972· OSTI ID:6506255

Judge, S M; Krusche, B; Schreckenbach, K ^[1]; Tsertos, H; Kienle, P ^[2]

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1. Institut Max von Laue-Paul Langevin (ILL), 156 X Centre de Tri, 38042 Grenoble CEDEX (France)
2. Gesellschaft fuer Schwerionenforschung (GSI), Planckstrasse 1, D-6100 Darmstadt (Federal Republic of Germany)

A search has been carried out for long-lived neutral particles which could be created in resonant {ital e}{sup +}{ital e}{sup {minus}} scattering, with an invariant mass around 1.8 MeV/{ital c}{sup 2}. A monoenergetic positron beam was scattered from a thin Be foil, and an active-shadow technique was used to suppress elastic {ital e}{sup +}{ital e}{sup {minus}} scattering. No evidence was found for neutral particles decaying dominantly into {ital e}{sup +}{ital e}{sup {minus}} pairs, in the lifetime region between 4.5{times}10{sup {minus}13} and 7.5{times}10{sup {minus}12} s (95% C.L.). This result, together with our previous work, eliminates recent theoretical models that have introduced new neutral particles in this mass region.

• OSTI ID: 6506255
• Journal Information: Physical Review Letters; (USA), Journal Name: Physical Review Letters; (USA) Vol. 65:8; ISSN PRLTA; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

645101* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Electromagnetic Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BHABHA SCATTERING
CROSS SECTIONS
DATA
ELASTIC SCATTERING
ELECTRODYNAMICS
ELECTRON SPECTROMETERS
ELECTRON-POSITRON INTERACTIONS
ENERGY RANGE
EXPERIMENTAL DATA
FIELD THEORIES
INFORMATION
INTERACTIONS
LEPTON-LEPTON INTERACTIONS
LIFETIME
LIMITING VALUES
MASS
MEASURING INSTRUMENTS
MEV RANGE
MEV RANGE 01-10
NUMERICAL DATA
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
QUANTUM ELECTRODYNAMICS
QUANTUM FIELD THEORY
SCATTERING
SPECTROMETERS