Degenerate Higgs bosons decays to ${\gamma\gamma}$ and ${Z\gamma}$ in the type II seesaw model

M. Chabab , Michel Capdequi-Peyranere (1) , L. Rahili

1 LUPM - Laboratoire Univers et Particules de Montpellier

Using the most recent results of CMS and ATLAS, we study the Higgs decays to γγ and Zγ in the scenario where the two CP even Higgs predicted by the type II seesaw model (HTM) are close to mass degenerate with a mass near 125 GeV. We analyse the effects of the Higgs potential parameters constrained by the full set of perturbative unitarity, boundedness from below (BFB) as well as from precision electroweak measurements on these decay modes. Our analysis demonstrates that the observed excess in the diphoton Higgs decay channel can be interpreted in our scenario within a delineated region controlled by λ1 and λ4 coupling. We also find a deviation in the Higgs decay to Zγ with respect to the Standard Model prediction and the largest enhancement is found for a ratio RZγ of the order 1.6. Furthermore we show that consistency with current ATLAS data on the diphoton decay channel favours a light doubly charged Higgs with mass in the range 92−180~GeV. Finally, we find that the γγ and Zγ Higgs decay modes are generally correlated and the magnitude of correlation is sensitive to the sign of the λ1 parameter.

Domaines: Physique des Hautes Energies - Phénoménologie [hep-ph]

M. Chabab, Michel Capdequi-Peyranere, L. Rahili. Degenerate Higgs bosons decays to ${\gamma\gamma}$ and ${Z\gamma}$ in the type II seesaw model. Physical Review D, 2014, 90, pp.035026. ⟨10.1103/PhysRevD.90.035026⟩. ⟨hal-01982710⟩