Analyticity Properties of Helicity Amplitudes
نویسندگان
چکیده
منابع مشابه
One loop multiphoton helicity amplitudes.
We use the solutions to the recursion relations for double-off-shell fermion currents to compute helicity amplitudes for n-photon scattering and electronpositron annihilation to photons in the massless limit of QED. The form of these solutions is simple enough to allow all of the integrations to be performed explicitly. For n-photon scattering, we find that unless n = 4, the amplitudes for the ...
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The program MadGraph is presented which automatically generates postscript Feynman diagrams and Fortran code to calculate arbitrary tree level helicity amplitudes by calling HELAS[1] subroutines. The program is written in Fortran and is available in Unix and VMS versions. MadGraph currently includes standard model interactions of QCD and QFD, but is easily modi ed to include additional models s...
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We apply the solution to the recursion relation for the double-off-shell quark current to the problem of computing one loop amplitudes with an arbitrary number of gluons. We are able to compute amplitudes for photon-gluon scattering, electron-positron annihilation to gluons, and gluon-gluon scattering via a quark loop in the case of like-helicity gluons. In addition, we present the result for t...
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ژورنال
عنوان ژورنال: Physical Review
سال: 1967
ISSN: 0031-899X
DOI: 10.1103/physrev.160.1251