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arXiv · 2410.17025

Testing Bell inequalities and probing quantum entanglement at CEPC

Youpeng Wu·Ruobing Jiang·Alim Ruzi·Yong Ban·Qiang Li
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Abstract

We study quantum entanglement and test violation of Bell-type inequality at the Circular Electron Positron Collider (CEPC), which is one of the most attractive future colliders. It's a promising particle collider designed to search new physics, make Standard Model (SM) precision measurements, and serving as a Higgs factory. Our study is based on a fast simulation of the $Z$ boson pair production from Higgs boson decay at $\sqrt{s} = 250$ GeV. The detector effects are also included in the simulation. The spin density matrix of the joint $ZZ$ system is parametrized using irreducible tensor operators and reconstructed from the spherical coordinates of the decay leptons. To test Bell inequalities, we construct observable quantities for the $H \to ZZ*$ process in CEPC by using the (Collins-Gisin-Linden-Massar-Popescu) CGLMP inequality, whose value is determined from the density matrix of the Z boson pairs. The sensitivity of the Bell inequality violation is observed with more than 1$\sigma$ and the presence of the quantum entanglement is probed with more than 2$\sigma$ confidence level.

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Youpeng Wu, Ruobing Jiang, Alim Ruzi, Yong Ban, Qiang Li. 2024-10-22. Testing Bell inequalities and probing quantum entanglement at CEPC. https://arxiv.org/abs/2410.17025

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