DETERMINATION OF $pi$$-$$pi$ CROSS SECTIONS BY THE CHEW-LOW EXTRAPOLATION METHOD

Journal Article · Wed Aug 01 04:00:00 EDT 1962 · Physical Review (U.S.) Superseded in part by Phys.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.127.959· OSTI ID:4789652

Carmony, D D; Van de Walle, R T

A discussion of the Chew-Low conjecture applied to reactions of the type pi + p yields pi + p + pi /sup o/given. The extrapolation technique and the so-called physical-regionplot method'' are discussed. These methods are then applied to a sample of 1684 interactions of the type pi /sup +/ + p yields pi /sup +/ + p + pi /sup o/ and 411 interactions of the type pi /sup -/ + p yields pi /sup -/ + p + pi /sup o/ at 1.25-Bev/c incident pion momentum. Details are presented of the way in which this sample was obtained and processed. The sigma /sub pi + pi /sup o/ physical-region plots for the pi + data confirm the existence of the now well-established T = J = 1 pi -- pi resonance at 725 plus or minus 25 Mev. On the other hand, the physical-region plot of the pi / sup -/ data shows strong deviations from the results expected on the basis of this same resonance. Extrapolation results are presented in detail for seven different pi -- pi energy regions. The pi /sup -/ and pi /sup +/ data (although very different in the physical region) extrapolate to the same pi -- pi cross section values for energy regions around the resonance. This fact and the general character of the pi /sup -/ extrapolations indicate that the pi / sup -/ physical-region distortions should be attributed to final-state interactions. Although the errors are large, the pi -- pi cross-section curve obtained by extrapolation on the combined pi /sup +/ pi /sup -/ sample, is in full agreement with the existence of a pi -- pi P-wave resonance at 725 plus or minus 25 Mev. (auth)

• Research Organization: Univ. of California, Berkeley
• NSA Number: NSA-16-029687
• OSTI ID: 4789652
• Journal Information: Physical Review (U.S.) Superseded in part by Phys.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 D, Journal Name: Physical Review (U.S.) Superseded in part by Phys.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: 127; ISSN PHRVA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CHEW-LOW METHOD
CROSS SECTIONS
ELEMENTARY PARTICLES
ERRORS
FIELD THEORY
INTERACTIONS
MOMENTUM
P-WAVE
PHYSICS
PIONS
PROTONS
QUANTUM MECHANICS
RESONANCE