Speaker
Description
Based on several features observed in the data collected during Run 1 of the LHC, a
simplified model was proposed in which a heavy scalar, H, decays into a combination of the
SM Higgs boson (h) and a new Higgs-like scalar, S. One implication of this model is the
appearance of excesses in lepton production when the decay S →WW dominates. These
excesses, referred to as the multi-lepton anomalies at the LHC, were subsequently identified.
They include events with two or more leptons, missing transverse energy, and (b)-jets in
the final state. Based on the invariant mass of lepton pairs, the mass of the new scalar is
predicted to be mS = 150 ±5 GeV.
The analysis of γγ, Zγ, and WW sideband spectra in Run 2 data confirms the presence
of a resonance at mS = 152 ±1 GeV, with a global significance of 5.3σ. This represents the
strongest excess observed at the LHC to date that is consistent with a narrow resonance be-
yond the SM. These findings strongly motivate further investigation at future high-precision
facilities such as the CEPC.
