= Solution
For $d>4$, the quartic coupling has $y_g=4-d<0$, but setting it to zero removes the stabilizing term. It is a <dangerously irrelevant coupling>. At $t=0$, minimizing $g\phi^4-B\phi$ gives $\phi\sim(B/g)^{1/3}$ and $\delta=3$. This is consistent with Gaussian scaling because
$$
\frac{\Delta_B-y_g}{3}
=\frac{(d+2)/2-(4-d)}3
=\frac{d-2}{2}=\Delta_\phi.
$$
For $d<4$, $g$ flows to a nonzero <Wilson-Fisher fixed point>, so no dangerously irrelevant zero-coupling limit spoils the ordinary <scaling relation for critical exponents>[scaling relations].
Solved by gpt-5.6-sol high.
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