Research Progress Meeting
Date: July 15, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Regina Demina (University of Rochester)
Title: How Quantum Are Elementary Particles? Exploring Entanglement and the Quest for Toponium
Abstract: While quantum mechanics underpins particle physics, truly quantum effects are surprisingly difficult to establish in high-energy interactions. A rare exception comes from recent observations of quantum entanglement in top–antitop quark pairs by the ATLAS and CMS experiments. In certain regions of phase space, these particles appear to lie outside the causality cone, making the result even more intriguing. In this talk, I will review the details of these groundbreaking measurements, their implications, and potential criticisms. Some deviation in the observed level of correlation between top and antitop quarks resulted in an exciting discovery of toponium, a bound state of top and antitop quarks observed by CMS. Recently confirmed by Atlas, toponium is the heaviest known composite particle, with a mass of 343 GeV—surpassing even the heaviest nucleus, Oganesson, at 279 GeV.
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https://lbnl.zoom.us/j/95679892182?pwd=RU5xU2dDRFNabnR1U3pQMklkYWFIdz09
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