The 2026 International Workshop on the High Energy Circular Electron Positron Collider

Testing Bell inequalities and probing quantum entanglement with H→ZZ at CEPC

Not scheduled

20m

Oral Presentation 06: Physics Beyond the SM Physics Beyond SM

Speaker

Alim Ruzi (school of physics Peking Uniersity)

Description

We explore quantum entanglement and Bell-inequality violation in Higgs decays at the CEPC, using simulated e+e−→ZH events at $\sqrt{s} = $ 250 GeV with 50 $\mathrm{ab}^−1$. From lepton angular distributions in $H\to ZZ^*\to$ 4ℓ, we reconstruct the ZZ spin-density matrix and test the CGLMP inequality for a two-qutrit system. Considering semileptonic and pure-leptonic associated-Z channels, we find the semileptonic mode offers the strongest sensitivity, with entanglement above $2\sigma$ and Bell violation above $1\sigma$, underscoring the CEPC’s strong potential for quantum tests with Higgs bosons.