LIFETIME OF THE NEUTRAL PION

Journal Article · Wed Feb 01 04:00:00 EST 1961 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.121.886· OSTI ID:4099433

Glaser, V; Ferrell, R A

As Primakoff noted, the phenomenological coupling constant of the neutral pion with the electromagnetic field can be investigated by considering the photoproduction of neutral pions in an external Coulomb fie1d. This is the inverse of the usual two-photon decay (one of the photons being provided by the external field). The relationship between the cross section and the free lifetime of the pi /sup 0/ was derived. Although the total cross section was small, it was found at high energy that the differential cross section was strongly peaked near the forward direction. The peak cross section was proportional to the fourth power of the photon energy. It was this feature that made possible an experimental determination of the lifetime by the photoproduction method to an accuracy of about l0%. A minimum photon energy of 1 Bev was required to avoid uncertainties in the nuclear form factor. A higher photon energy wou1d be necessary only if the pi /sup 0/ mean life was greater than 5x 10/sup -17/ sec. The backgrounds to be expected from nuclear photoproduction were estimated and found to be sufficiently small. In particular, the interference between the coherent nuclear pi /sup 0/ photoprcduction and the Primakoff process was not excessive. (auth)

• Research Organization: European Organization for Nuclear Research, Geneva
• NSA Number: NSA-15-009714
• OSTI ID: 4099433
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Journal Name: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D Vol. Vol: 121; ISSN PHRVA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BACKGROUND
COUPLING CONSTANTS
CROSS SECTIONS
ELECTRIC FIELDS
ELECTROMAGNETIC FIELDS
ENERGY
FORM FACTOR
INTERACTIONS
LIFETIME
PHOTOPRODUCTION
PHYSICS
PIONS
PIONS-NEUTRAL
PRIMAKOFF EFFECT
VARIATIONS