Test of an Equivalence Theorem at One-Loop

Abstract

We show that the equivalence theorem approximating one-loop gauge sector diagrams by including only Goldstone bosons in the loop gives a remarkably poor approximation to the amplitude for the decay $H\to \gamma \gamma$ and for the process $\gamma \gamma \to HH$. At one loop, large logarithms can arise that evade power counting arguments.

Comments: 8 pages + 4 figures available on request, MAD/PH/712