Loop-induced h -> gamma gamma, Z gamma, gg decays in 3-Higgs doublet models


INTERNATIONAL JOURNAL OF MODERN PHYSICS A, vol.37, no.13, 2022 (Peer-Reviewed Journal) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 37 Issue: 13
  • Publication Date: 2022
  • Doi Number: 10.1142/s0217751x22500671
  • Journal Indexes: Science Citation Index Expanded, Scopus, Academic Search Premier, Environment Index, INSPEC, zbMATH
  • Keywords: Extension of the Higgs sector, Higgs phenomenology, additional Higgs bosons, ELECTROWEAK SYMMETRY-BREAKING, HIGGS-BOSON, ANATOMY


In this paper, we analyze the loop-induced decays of neutral Higgs boson h into pairs of photons, gluons and Z gamma in 3-Higgs Doublet Models (3HDMs), where all the doublets have nonzero vacuum expectation values. In the 3HDM, there are contributions to these decays from loops of charged scalars H-1,2(+/-) that are not present in the Standard Model. We find an enhancement in the channel h -> Z gamma with respect to the Standard Model prediction in some parameter region while respecting constraints from the measurements of h -> gamma gamma at the LHC. The charged Higgs bosons H-1,2(+/-) lead to the enhancement of Z gamma decay mode in some part of the parameter space of the 3HDM. Then, we discuss the correlations between the decay modes h -> Z gamma and h -> gamma gamma. Moreover, we study Type-I and Type-Z of 3HDMs and find that these types of 3HDMs can be distinguished via only the gluonic decays, since the contributions of the H-1,2(+/-) loops are dominant to those of fermion loops. We also investigate the effects of the model parameters on these loop-induced decays. As an interesting phenomenological consequence, the 3HDM is dominantly governed by the parameters: two ratios of vacuum expectation values (VEVs); tan gamma, tan beta and the mixing angles of the CP-even Higgs bosons, alpha(1,2) and theta.