Testing Bell inequalities and probing quantum entanglement at a muon collider

• Published in: The journal of high energy physics Vol. 2024; no. 10; pp. 211 - 14
• Main Authors: Ruzi, Alim, Wu, Youpeng, Ding, Ran, Qian, Sitian, Levin, Andrew Micheal, Li, Qiang
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 29-10-2024; Springer Nature B.V; SpringerOpen
• Subjects: Bell's inequality; Bosons; Classical and Quantum Gravitation; Density; Electroweak Precision Physics; Elementary Particles; Higgs Production; Higgs Properties; Kinematics; Large Hadron Collider; Leptons; Monte Carlo simulation; Muons; Particle decay; Particle physics; Physics; Physics and Astronomy; Quantum entanglement; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Quarks; Regular Article - Theoretical Physics; Relativity Theory; Simulation; String Theory; Higgs Production; Electroweak Precision Physics; Higgs Properties
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP10(2024)211

A
bstract
A muon collider represents a promising candidate for the next generation of particle physics experiments after the expected end of LHC operations in the early 2040s. Rare or hard-to-detect processes at the LHC, such as the production of multiple gauge bosons, become accessible at a TeV muon collider. We present here the prospects of detecting quantum entanglement and the violation of Bell inequalities in
H
→
ZZ
→ 4
ℓ
events at a potential future muon collider. We show that the spin density matrix of the Z boson pairs can be reconstructed using the kinematics of the charged leptons from the Z boson decays. Once the density matrix is determined, it is straightforward to obtain the expectation values of various Bell operators and test the quantum entanglement between the Z boson pair. Through a detailed study based on Monte-Carlo simulation, we show that the generalized CGLMP inequality can be maximally violated, and testing Bell inequalities could be established with high significance.