Direct search for two-photon decay modes of orthopositronium

Journal Article · Sun Mar 10 23:00:00 EST 1991 · Physical Review Letters; (USA)

DOI:https://doi.org/10.1103/PhysRevLett.66.1302· OSTI ID:5755288

Gidley, D W; Nico, J S; Skalsey, M ^[1]

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1. Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (US)

A direct search for {gamma} rays from the forbidden decay {ital o}-Ps{r arrow}2{gamma} has been performed using the same apparatus that recently measured an anomalously high {ital o}-Ps decay rate. Using a high-resolution Ge {gamma}-ray detector, a 233-ppm limit is set on the branching ratio to a pair of 511-keV {gamma} rays, and a 200-ppm limit is set on the branching ratio pair of unequal-energy {gamma} rays that sum to 1022 keV. Hence, these 2{gamma} modes cannot be responsible for the {ital o}-Ps decay-rate discrepancy between theory and experiment of 1400{plus minus}230 ppm.

• OSTI ID: 5755288
• Journal Information: Physical Review Letters; (USA), Journal Name: Physical Review Letters; (USA) Vol. 66:10; ISSN PRLTA; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

640303* -- Atomic
Molecular & Chemical Physics-- Positronium
Muonium
& Muonic & Mesic Atoms & Molecules
645400 -- High Energy Physics-- Field Theory
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
74 ATOMIC AND MOLECULAR PHYSICS
ALKALINE EARTH METAL COMPOUNDS
ANNIHILATION
BASIC INTERACTIONS
CAVITIES
CHALCOGENIDES
CORRELATIONS
DATA
ELECTRODYNAMICS
ELECTROMAGNETIC INTERACTIONS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ELEMENTS
ENERGY SPECTRA
EXPERIMENTAL DATA
FIELD THEORIES
GAMMA RADIATION
GERMANIUM
INFORMATION
INTERACTIONS
IONIZING RADIATIONS
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MASSLESS PARTICLES
MEASURING INSTRUMENTS
METALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHOTONS
POSITRONIUM
QUANTUM ELECTRODYNAMICS
QUANTUM FIELD THEORY
RADIATION DETECTORS
RADIATIONS
RESOLUTION
SCINTILLATION COUNTERS
SEMICONDUCTOR DETECTORS
SPECTRA
TESTING