(γ, 3π) Vertex and Double π ⁰ Photoproduction

Journal Article · Thu Nov 01 04:00:00 EST 1962 · Progress of Theoretical Physics (Kyoto)

DOI:https://doi.org/10.1143/PTP.28.915· OSTI ID:4708104

Itabashi, Kiyomi; Ebata, Takeshi

Effects of the ( γ ,3 π ) vertex in the reaction γ + p → p + 2 π ⁰ is studied. It is shown that the ( γ ,3 π )-part of the amplitude for this reaction is given by the meson current part'' of the amplitude for the single pi /sup 0/ production by a virtual photon, multiplied by a certain numerical factor including the effective coupling constant of the ( γ ,3 π ) vertex. Thus Thus referring to the theory of Fubini, Nambu, and Wataghin for the single pion electroproduction, the ( γ ,3 π )-part of the double pi ⁰ photoproduction amplitude can be obtained almost exactiy. It is also shown that, under appropriate experimental conditions, the major contribution to the reaction γ + p → p + 2 π /sup 0/ comes from the absorption of the incident photons via the ( γ ,3 π ) vertex, unless its effective coupling constant lambda be much smaller than the value expected from the simple perturbation calculation. Thus, the experimental study of this reaction would possibly provide an alternative and rather unambiguous method for the determination of lambda . An example for such a measurement is proposed, and the cross section under the proposed conditions is calculated.

• Research Organization: Tokyo Univ.
• Sponsoring Organization: USDOE
• NSA Number: NSA-17-011565
• OSTI ID: 4708104
• Journal Information: Progress of Theoretical Physics (Kyoto), Journal Name: Progress of Theoretical Physics (Kyoto) Journal Issue: 5 Vol. 28; ISSN 0033-068X
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION
COUPLING CONSTANTS
CROSS SECTIONS
FIELD THEORY
GAMMA RADIATION
INTERACTIONS
MEASURED VALUES
NUMERICALS
PERTURBATION THEORY
PHOTONS
PHOTOPRODUCTION
PIONS
PROTONS