2024/07/25 by Degrassi, Giuseppe, Slavich, Pietro · 1 citation
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2407.18185
We compute the two-loop BSM contributions to the h\longrightarrow γγ decay width in the SM extended with a real triplet of SU(2). We consider scenarios in which the neutral components of doublet and triplet do not mix, so that the lighter neutral scalar h has (at least approximately) SM-like couplings to fermions and gauge bosons. We focus on the two-loop corrections controlled by the quartic scalar couplings, and obtain explicit and compact formulas for the h γγ amplitude by means of a low-energy theorem that connects it to the derivative of the photon self-energy w.r.t. the Higgs field. We briefly discuss the numerical impact of the newly-computed contributions, showing that they may be required for a precise determination of Γ[h→ γγ] in scenarios where the quartic scalar couplings are large.