# Soft-Supersymmetry Mass (Direct contact term)

I found this term/operator in some papers that can generate masses, e.g Riva-Biggio-Pomarol(2012), Fox-Nelson-Weiner

$\int d^4\theta \frac{X^\dagger X}{M^2}Q^\dagger Q$

The term give a mass for the squarks. This is easy to see by expanding the superfields, $$\frac{ F ^4 }{ M ^4 }\int \,d^4\theta \bar{\theta} ^2 \theta ^2 \left( \tilde{q} ^\dagger + \bar{\theta} \bar{q} + ... \right) \left( \tilde{q} + \theta q + ... \right)$$ Only the first squark-squark term survives giving, $$m _{ \tilde{q} } ^2 \tilde{q} ^\dagger \tilde{q}$$ where $m _{ \tilde{q} } ^2 \equiv F ^4 / M ^4$ (there is an implicit numerical coefficient outfront as well).