We compute the two-loop BSM contributions to the h⟶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 hγγ 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.
Degrassi, G., Slavich, P. (2025). On the two-loop BSM corrections to h⟶γγ in a triplet extension of the SM. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 85(1), 49 [10.1140/epjc/s10052-025-13758-1].
On the two-loop BSM corrections to h⟶γγ in a triplet extension of the SM
Degrassi G.;
2025-01-01
Abstract
We compute the two-loop BSM contributions to the h⟶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 hγγ 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
