On distinguishing radions from Higgs bosons

Radion couplings are almost identical in form to Higgs boson couplings, making it very difficult to distinguish the two states when the masses and branching ratios to Standard Model particles are similar. The only real difference lies in the fact that the coupling of radions to off-shell fermions is proportional to the momentum rather than the mass of the fermion. This extra contribution gets cancelled in all tree-level processes and shows up only in loop-induced processes like Φ→γγ and Φ→gg. We perform a careful calculation of these branching ratios and establish that they can prove crucial in clearly distinguishing a radion from a Higgs boson. This claim is made concrete by evaluating the exclusive cross-sections in a radiative process involving elementary scalars.