- #1

dimitronic

- 2

- 0

**relative minus sign??**

Hi, I have one question for you...

to compute the matrix element for the process u d -> u d I want to use full SM, but I have one problem I'll give you the maths.

process with W:

<ud|(\bar{Ψ}

_{u}Ψ

_{d})(\bar{Ψ}

_{d}Ψ

_{u})|ud>

process with γ:

<ud|(\bar{Ψ}

_{u}Ψ

_{u})(\bar{Ψ}

_{d}Ψ

_{d})|ud>

Z and g are the same with γ (i don't write the propagators and the Lorentz parts for simplicity).

Is there a minus sign between W and the others??

I say yes ... but i am not sure.