Projects per year
Abstract
Entanglement is a key feature of quantum mechanics1–3, with applications in fields such as metrology, cryptography, quantum information and quantum computation4–8. It has been observed in a wide variety of systems and length scales, ranging from the microscopic9–13 to the macroscopic14–16 . However, entanglement remains largely unexplored at the highest accessible energy scales. Here we report the highest-energy observation of entanglement, in top–antitop quark events produced at the Large Hadron Collider, using a proton–proton collision dataset with a centre-of-mass energy of √s = 13 TeV and an integrated luminosity of 140 inverse femtobarns (fb)−1 recorded with the ATLAS experiment. Spin entanglement is detected from the measurement of a single observable D, inferred from the angle between the charged leptons in their parent top- and antitop-quark rest frames. The observable is measured in a narrow interval around the top–antitop quark production threshold, at which the entanglement detection is expected to be significant. It is reported in a fiducial phase space defined with stable particles to minimize the uncertainties that stem from the limitations of the Monte Carlo event generators and the parton shower model in
modelling top-quark pair production. The entanglement marker is measured to be D = −0.537 ± 0.002 (stat.) ± 0.019 (syst.) for m340 GeV < < 380 GeVtt . The observed result is more than five standard deviations from a scenario without entanglement and hence constitutes the first observation of entanglement in a pair of quarks and the highest-energy observation of entanglement so far.
modelling top-quark pair production. The entanglement marker is measured to be D = −0.537 ± 0.002 (stat.) ± 0.019 (syst.) for m340 GeV < < 380 GeVtt . The observed result is more than five standard deviations from a scenario without entanglement and hence constitutes the first observation of entanglement in a pair of quarks and the highest-energy observation of entanglement so far.
Original language | English |
---|---|
Pages (from-to) | 542-547 |
Number of pages | 6 |
Journal | Nature |
Volume | 633 |
Issue number | 8030 |
DOIs | |
Publication status | Published - 18 Sept 2024 |
Fingerprint
Dive into the research topics of 'Observation of quantum entanglement with top quarks at the ATLAS detector'. Together they form a unique fingerprint.-
Upgrade of the ATLAS detector at the LHC (2023-26)
Clark, P. (Principal Investigator)
Science and Technology Facilities Council
1/04/23 → 31/03/26
Project: Research
-
Experimental Particle Physics at the University of Edinburgh
Leonidopoulos, C. (Principal Investigator)
Science and Technology Facilities Council
1/04/23 → 31/03/26
Project: Research
-
Experimental Particle Physics at the University of Edinburgh
Leonidopoulos, C. (Principal Investigator)
Science and Technology Facilities Council
1/10/22 → 31/03/26
Project: Research