Bootstrapping one-loop QCD amplitudes with general helicities

Journal Article · Tue Aug 01 04:00:00 EDT 2006 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.74.036009· OSTI ID:20870924

Berger, Carola F; Bern, Zvi; Dixon, Lance J; Forde, Darren; Kosower, David A ^[1]

---

1. Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309 (United States)

The recently developed on-shell bootstrap for computing one-loop amplitudes in nonsupersymmetric theories such as QCD combines the unitarity method with loop-level on-shell recursion. For generic helicity configurations, the recursion relations may involve undetermined contributions from nonstandard complex singularities or from large values of the shift parameter. Here we develop a strategy for sidestepping difficulties through the use of pairs of recursion relations. To illustrate the strategy, we present sets of recursion relations needed for obtaining n-gluon amplitudes in QCD. We give a recursive solution for the one-loop n-gluon QCD amplitudes with three or four color-adjacent gluons of negative helicity and the remaining ones of positive helicity. We provide an explicit analytic formula for the QCD amplitude A{sub 6;1}(1{sup -},2{sup -},3{sup -},4{sup +},5{sup +},6{sup +}), as well as numerical results for A{sub 7;1}(1{sup -},2{sup -},3{sup -},4{sup +},5{sup +},6{sup +},7{sup +}), A{sub 8;1}(1{sup -},2{sup -},3{sup -},4{sup +},5{sup +},6{sup +},7{sup +},8{sup +}), and A{sub 8;1}(1{sup -},2{sup -},3{sup -},4{sup -},5{sup +},6{sup +},7{sup +},8{sup +}). We expect the on-shell bootstrap approach to have widespread applications to phenomenological studies at colliders.

• OSTI ID: 20870924
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 3 Vol. 74; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
BOOTSTRAP MODEL
COLOR MODEL
GLUONS
HELICITY
MATHEMATICAL SOLUTIONS
QUANTUM CHROMODYNAMICS
RECURSION RELATIONS
SINGULARITY
UNITARITY