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I am trying to compute the crosssection for the diagram below with a divergent triangle loop:
where ##X^0## and ##X^## are some fermions with zero and negative charge respectively. I am interested in low energy limits, so you can consider Wpropagator as ##\frac {i\eta_{\mu\nu}} {M_w^2}##.
When computing the amplitude, you end of with an integration of the form:
$$ \int \frac {k_\mu \gamma^\mu +m_} {k^2 m_^2} \frac {d^4 k} {(2\pi)^4} $$
where ##m_## is mass of ##X^##.
Any ideas how to find the amplitude in terms of kinematic parameters, masses etc?
where ##X^0## and ##X^## are some fermions with zero and negative charge respectively. I am interested in low energy limits, so you can consider Wpropagator as ##\frac {i\eta_{\mu\nu}} {M_w^2}##.
When computing the amplitude, you end of with an integration of the form:
$$ \int \frac {k_\mu \gamma^\mu +m_} {k^2 m_^2} \frac {d^4 k} {(2\pi)^4} $$
where ##m_## is mass of ##X^##.
Any ideas how to find the amplitude in terms of kinematic parameters, masses etc?
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