One of the important roles of the SM Higgs boson is to keep WW scattering
amplitudes perturbatively unitary in high energy limit. However, once the Higgs
coupling deviates from the SM prediction, the perturbative unitarity might be
broken down at the certain energy scale. In order to maintain the perturbative
unitarity with anomalous higgs coupling in high energy limit, we need new particle(s)
whose couplings are tuned to cancel a bad behavior of WW scattering amplitudes.
The required conditions are called “unitarity sum rules”. We revisit the unitarity sum
rules and apply them to investigate the model independent property of perturbative
extra spin-0,1 particles.