How to write a 4x4 coupling matrix in a FeynArts model file

Hassiba · Dec 19, 2017

Hi;
Thank you so much in advance for any help.
My question about FeynArts model file, I have coupling of my model and I did arrive to insert (write) constant 4*4matrix in generic model file in Feynarts or I should write it in model file.
Thanks again

Hassiba · Dec 19, 2017

These are couplings of my model:

$Typeset equation: the relative Feynman rule for the e(p_in) - e(p_out) - gamma(k) vertex Theta is = i e Q_f [ gamma_mu - (i/2) k^nu (Theta_{mu nu rho} p_in^rho - Theta_{mu nu} m_f) ].$

Equation for the vertex e(p_in) - e(p_out) - Z(k) = ie/(sin 2θ_W) times a curly-bracketed expression involving γ_μ, k^ν Θ_μνρ p_in^ρ, C_V,f and C_A,f γ5, and a second term with Θ_μν m_f.

$Equation: with Θ_{μνρ} = Θ_{μνγ_ρ} + Θ_{νργ_μ} + Θ_{ρμγ_ν}.$

but I have assumed $\theta^{\mu\nu}$ as matrix as following :

$\theta^{\mu\nu}$
=\begin{pmatrix}
0 & -1 & -1 & -1 \\

1 & 0 & -1 & 1 \\

1 & 1 & 0 & -1 \\

1 & -1 & 1 & 0

\end{pmatrix}

Would you please help me how can I insert this matrix (write this matrix in FeynArts) in this case.

Thank you so much for your help

How to write a 4x4 coupling matrix in a FeynArts model file

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