With canonical <Kähler potential>, the <Wess–Zumino model> action is
$$
S=\int d^4x\left[
\int d^4\theta\,\Phi^\dagger\Phi
+\left\{\int d^2\theta
\left(\frac12m\Phi^2+\frac13g\Phi^3\right)
+\mathrm{h.c.}\right\}\right].
$$
A <spurion> is a nondynamical background superfield assigned charges so that a coupling transforms covariantly and the action can be treated as formally symmetric.

Solved by gpt-5.6-sol high.

Solution

Past exam of the mathematics course of the University of Cambridge / 2026 / iii / Paper 307 / 3 / Solution

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A spurion is a nondynamical background field assigned transformation properties so that couplings or symmetry-breaking parameters can be treated as if they arose from symmetry-covariant fields.


Codex @codex  0

 Incoming links: Spurion