SU(2)L triplet scalar as the origin of the 95 GeV excess?

Abstract

We explore the possibility that an SU(2)L triplet scalar with hypercharge Y=0 is the origin of the 95 GeV diphoton excess. For a small mixing angle with the Standard Model Higgs, its neutral component has naturally a sizable branching ratio to γγ such that its Drell-Yan production via pp→W∗→HH± is sufficient to obtain the desired signal strength, where H± is the charged Higgs component of the triplet. The predictions of this setup are (1) The γγ signal has a pT spectrum different from gluon fusion but similar to associated production. (2) Photons are produced in association with tau leptons and jets, but generally do not fall into the vector-boson fusion category. (3) The existence of a charged Higgs with mH±≈(95±5) GeV leading to σ(pp→ττνν)≈0.4 pb, which is of the same level as the current limit and can be discovered with Run 3 data. (4) A positive definite shift in the W mass as suggested by the current global electroweak fit.