Four-photon decay of orthopositronium: A test of charge-conjugation invariance

Journal Article · Sun Sep 01 00:00:00 EDT 1996 · Physical Review A

DOI:https://doi.org/10.1103/PhysRevA.54.1952· OSTI ID:383129

Yang, J; Chiba, M; Hamatsu, R; Hirose, T; Matsumoto, T; Yu, J ^[1]

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1. Department of Physics, Tokyo Metropolitan University, 1-1 Minami Ohsawa, Hachioji-shi, Tokyo 192-03 (Japan)

Charge-conjugation ({ital C}) invariance demands that ortho- and parapositronium decay into an odd number and an even number of photons, respectively. For the test of the {ital C} invariance, we searched for a {ital C}-violating process, i.e., four-photon decay from orthopositronium, using a multi-{gamma}-ray spectrometer. No {ital C}-violating process was observed leading to the upper limit as 2.6{times}10{sup {minus}6} at 90{percent} confidence level for the branching ratio of four- to three-photon decays from orthopositronium. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 383129
• Journal Information: Physical Review A, Journal Name: Physical Review A Journal Issue: 3 Vol. 54; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BRANCHING RATIO
C INVARIANCE
GAMMA SPECTRA
LEPTONIC DECAY
POSITRONIUM
QUANTUM ELECTRODYNAMICS
WEAK INTERACTIONS