Speaker
Description
Ref. https://arxiv.org/abs/2406.01656
A combination of searches for Higgs boson decaying into a visible photon and a massless dark photon (H→γγ$_{d}$) is presented using 139 fb$^{-1}$ of proton--proton collision data at a centre-of-mass energy of √s = 13 TeV recorded by the ATLAS detector at the Large Hadron Collider. The observed (expected) 95% confidence level upper limit on the Standard Model Higgs boson decay branching ratio is determined to be Br(H→γγ$_{d}$)< 1.3% (1.5)%. The search is also sensitive to higher-mass Higgs bosons decaying into the same final state. The observed (expected) 95% CL limit on the cross section times branching ratio ranges from 16 fb (26 fb) for $m_H$ = 400 GeV to 1.0 fb (1.5 fb) for $m_H$ = 3 TeV. Results are also interpreted in the context of a minimal simplified model.
