ANALYTIC PROPERTIES OF PERTURBATION EXPANSIONS

Journal Article · Fri Jan 01 04:00:00 EST 1960 · Physical Review (U.S.) Superseded in part by Phys.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.117.261· OSTI ID:4202136

Taylor, J C

A method is introduced for locating and interpreting the singularities in finite-order perturbation expansions of Green's functions, in cases where the external momenta are complex vectors with real scalar products. In particular. when the external momenta form a real Euclidean set, there is a simple graphical construction, applicable to all finite orders. As an example of a case in which the external momenta form a real set in a space of signature scattering amplitudes is interpreted in perturbation theory. Finally, the ranges of values of momentum-transfer for which (in perturbation theory) dispersion relations certainly hold are enlarged, in particular by using the fact that the pion is pseudoscalar. (auth)

• Research Organization: Imperial Coll. of Science and Tech., London
• NSA Number: NSA-14-011025
• OSTI ID: 4202136
• Journal Information: Physical Review (U.S.) Superseded in part by Phys.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 D, Journal Name: Physical Review (U.S.) Superseded in part by Phys.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: 117; ISSN PHRVA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

DISPERSION RELATIONS
ELEMENTARY PARTICLES
FIELD THEORY
GREEN FUNCTION
MANDELSTAM REPRESENTATION
MOMENTUM
PARTICLE MODELS
PERTURBATION THEORY
PHYSICS
PIONS
SCATTERING
VECTORS