Kinematical constraints of helicity amplitudes

نویسندگان

چکیده

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Kinematical Constraints of He Licity Amplitudes

The kinematical constraints of helicity amplitudes are studied using the general ideas of Jackson and Hite. The helicity amplitudes are expressed in terms of a Taylor ser ies expansion from which all constraints at threshold and pseudothreshold can be tr ivial ly found. The simplicity of this approach is i l lustrated by deriving all of the constraints for 7rp --* N~ and ~rp --* AN.

متن کامل

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 ...

متن کامل

Automatic Generation of Tree Level Helicity Amplitudes

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...

متن کامل

Helicity Amplitudes for Single-Top Production

Single top quark production at hadron colliders allows a direct measurement of the top quark charged current coupling. We present the complete tree-level helicity amplitudes for four processes involving the production and semileptonic decay of a single top quark: W -gluon fusion, flavor excitation, s-channel production and W associated production. For the first three processes we study the qual...

متن کامل

Multigluon helicity amplitudes involving a quark loop.

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...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Nuclear Physics B

سال: 1969

ISSN: 0550-3213

DOI: 10.1016/0550-3213(69)90253-3