"Quantum Entanglement and Violation of Bell Inequality at High Energies"
Prof. Emidio Gabrielli
Department of Physics, University of Trieste (Italy)

Thursday 28/9/2023 16:00
Aula A, Dipartimento di Fisica

We present here novel and groundbreaking results that establish for the first time quantum mechanics non-locality at high energy and for strong and weak forces. We focus on a mathematical inequality, devised by J. S. Bell in 1964, relating the probabilities of different measurements on a given system. It is satisfied by local, deterministic theories and violated by quantum mechanics. This violation originates from the surprising property of non-locality featured by quantum mechanics, that is, states that have interacted in the past maintain a degree of entanglement far more extensive than that expected from the corresponding classical correlations. The Bell inequality has been tested at low energy with photons - the work was awarded, the Nobel Prize in Physics in 2022 - but no actual test has been performed at higher energies and in the presence of strong and weak interactions until now. We use the analysis published by the LHCb collaboration at CERN Large Hadron Collider (LHC) on the helicity amplitudes for the decay of the B-meson into J/Psi K* to show that the Bell inequality is violated in the process with a large significance (36 standard deviations) - thereby firmly establishing for the first time this distinguishing feature of quantum mechanics at high energies in a collider setting and in the presence of strong and weak interactions. Results on other potential tests of Bell inequalities at higher energies that can be performed at the LHC will be also shown.