Published June 15, 2007 | Version v1
Journal article

Direct extraction of one-loop integral coefficients

Creators

  • 1. Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309, USA and Department of Physics and Astronomy, UCLA, Los Angeles, California 90095-1547 (United States)

Description

We present a general procedure for obtaining the coefficients of the scalar bubble and triangle integral functions of one-loop amplitudes. Coefficients are extracted by considering two-particle and triple unitarity cuts of the corresponding bubble and triangle integral functions. After choosing a specific parametrization of the cut loop momentum we can uniquely identify the coefficients of the desired integral functions simply by examining the behavior of the cut integrand as the unconstrained parameters of the cut loop momentum approach infinity. In this way we can produce compact forms for scalar integral coefficients. Applications of this method are presented for both QCD and electroweak processes, including an alternative form for the recently computed three-mass triangle coefficient in the six-photon amplitude A6(1-,2+,3-,4+,5-,6+). The direct nature of this extraction procedure allows for a very straightforward automation of the procedure

Additional details

Publishing Information

Journal Title
Physical Review. D, Particles Fields
Journal Volume
75
Journal Issue
12
Journal Page Range
p. 125019-125019.20
ISSN
0556-2821
CODEN
PRVDAQ

INIS

Country of Publication
United States
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
38090854
Subject category
S72: PHYSICS OF ELEMENTARY PARTICLES AND FIELDS;
Descriptors DEI
EXTRACTION; FUNCTIONS; INTEGRALS; MASS; PHOTONS; QUANTUM CHROMODYNAMICS; SCALARS; UNITARITY
Descriptors DEC
BOSONS; ELEMENTARY PARTICLES; FIELD THEORIES; MASSLESS PARTICLES; QUANTUM FIELD THEORY; SEPARATION PROCESSES

Optional Information

Notes
(c) 2007 The American Physical Society