document: Since perturbative expansion is used, it is impossible to find the exact bounds; instead, one can derive tree-level unitarity bounds or loop-improved unitarity bounds. In this study, we will use unitarity bounds coming from a tree-level analysis [20]. This tree level analysis is derived with the help of the equivalence theorem [21], which itself is a high-energy approximation where it is assumed that the energy scale is much larger than the Z0 and W± gauge-boson masses. We will consider here this “high-energy” hypothesis that both the equivalence theorem and the decoupling regime are well settled, but in such a way that the unitarity constraint is also fulfilled. Our purpose is to investigate the quantum effects in the decays of the light CP-even Higgs boson h0, especially looking for sizeable differences with respect to the SM in the decoupling regime.
extractive_keyphrases: decoupling regime equivalence theorem exact bounds h0 higgs boson perturbative expansion quantum effects sm tree level analysis unitarity bounds unitarity constraint
abstractive_keyphrases: decays of the light cp-even higgs boson h0 gauge-boson masses high-energy approximation investigate the quantum effects in the decays of the light cp-even higgs boson h0 looking for sizeable differences with respect to the sm in the decoupling regime loop-improved unitarity bounds tree-level analysis tree-level unitarity bounds