•The amplitude

Calculation of the amplitude:

CreateFCAmp[inserttops, EqualMasses -> True, Sum -> False] // DotSimplify

{-((g _ A^( ))^2 ϕ ( -p _ 3 , m _ N^(ó  ) ) . (γ · ( p _ 2 + p _ 4 )) . ϕ ( p _ 1 , m _ N^(ó  ) ) ϕ ( -p _ 4 , m _ N^(ó  ) ) . (-(γ · ( p _ 2 + p _ 4 ))) . ϕ ( p _ 2 , m _ N^(ó  ) ) σ _ (j _ 3 j _ 1)^I _ 1 σ _ (j _ 4 j _ 2)^I _ 1)/(4 (f _ π^(ó  ))^2 ((-p _ 2 - p _ 4)^2 - (m _ π^(ó  ))^2)), ((g _ A^( ))^2 ϕ ( -p _ 3 , m _ N^(ó  ) ) . (-(γ · ( p _ 2 + p _ 3 ))) . ϕ ( p _ 2 , m _ N^(ó  ) ) ϕ ( -p _ 4 , m _ N^(ó  ) ) . (γ · ( p _ 2 + p _ 3 )) . ϕ ( p _ 1 , m _ N^(ó  ) ) σ _ (j _ 3 j _ 2)^I _ 1 σ _ (j _ 4 j _ 1)^I _ 1)/(4 (f _ π^(ó  ))^2 ((-p _ 2 - p _ 3)^2 - (m _ π^(ó  ))^2))}

Converted by Mathematica  (July 10, 2003)