Projection scheme for handling large-number cancellation related to gauge invariance

Journal Article · Sun Dec 01 04:00:00 EST 1996 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.54.6963· OSTI ID:397767

Chang, C; Ding, Y; Li, X; Wang, J; Zhu, J ^[1]

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1. China Center of Advanced Science and Technology (World Laboratory), P.O. Box 8730, Beijing 100080 (China)

A scheme, the so-called {open_quote}{open_quote}projection,{close_quote}{close_quote} for handling singularities in processes such as {ital e}{sup +}{ital e}{sup {minus}}{r_arrow}{ital t{bar b}e{sup {minus}}}{bar {nu}} (or {ital e}{sup +}{ital e}{sup {minus}}{r_arrow}{ital u{bar d}e{sup {minus}}}{bar {nu}}) is proposed. In the scheme, with the help of gauge invariance, the large power quantities ({ital s}/{ital m}{sup 2}{sub {ital e}}){sup {ital n}} ({ital n}{ge}1;{ital s}{r_arrow}{infinity}) are removed from the calculation totally, while in the usual schemes the large quantities appear and only will be canceled at last. The advantages of the scheme in numerical calculations are obvious; thus, we focus our discussions mainly on the advantages of the scheme in the special case where the absorptive part for some propagators relevant to the process could not be ignored, and a not satisfactory but widely adopted approximation is made; i.e., a finite constant {open_quote}{open_quote}width{close_quote}{close_quote} is introduced to approximate the absorptive part of the propagators phenomenologically even though QED gauge invariance is violated. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 397767
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 11 Vol. 54; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ANTINEUTRINOS
ELECTRON-POSITRON INTERACTIONS
ELECTRONS
GAUGE INVARIANCE
PROPAGATOR
QUARKS
SINGULARITY
T QUARKS
U QUARKS