**Next message:**hayam yassin: "How i can calculate the branching ratio by Feyncalc?"**Previous message:**Jorge Romão: "FeynCalc and Mathematica 7"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]**Mail actions:**[ respond to this message ] [ mail a new topic ]

Ussualy one replace the sum over polarization vectors with -g_{\mu \nu} for a massless particle (abelian).

For a particle with mass, \frac{k^{\mu } k^{\nu }}{k^{2}}-g^{\mu \nu }.

How can i get only the transversal polarization? or the longitudinal?

Thanks in advance

**Next message:**hayam yassin: "How i can calculate the branching ratio by Feyncalc?"**Previous message:**Jorge Romão: "FeynCalc and Mathematica 7"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]**Mail actions:**[ respond to this message ] [ mail a new topic ]

*
This archive was generated by hypermail 2b29
: 06/24/18-03:00:06 AM Z CEST
*