Revealing Bell’s nonlocality for unstable systems in high energy physics

  • Beatrix C. HiesmayrEmail author
  • Antonio Di Domenico
  • Catalina Curceanu
  • Andreas Gabriel
  • Marcus Huber
  • Jan-Åke Larsson
  • Pawel Moskal
Open Access


Entanglement and its consequences—in particular the violation of Bell inequalities, which defies our concepts of realism and locality—have been proven to play key roles in Nature by many experiments for various quantum systems. Entanglement can also be found in systems not consisting of ordinary matter and light, i.e. in massive meson–antimeson systems. Bell inequalities have been discussed for these systems, but up to date no direct experimental test to conclusively exclude local realism was found. This mainly stems from the fact that one only has access to a restricted class of observables and that these systems are also decaying. In this Letter we put forward a Bell inequality for unstable systems which can be tested at accelerator facilities with current technology. Herewith, the long awaited proof that such systems at different energy scales can reveal the sophisticated “dynamical” nonlocal feature of Nature in a direct experiment gets feasible. Moreover, the role of entanglement and \(\mathcal{CP}\) violation, an asymmetry between matter and antimatter, is explored, a special feature offered only by these meson–antimeson systems.


Entangle State Bell Inequality Accelerator Facility Neutral Kaon Conclusive Test 
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© The Author(s) 2012

Open AccessThis is an open access article distributed under the terms of the Creative Commons Attribution Noncommercial License (, which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.

Authors and Affiliations

  • Beatrix C. Hiesmayr
    • 1
    Email author
  • Antonio Di Domenico
    • 2
  • Catalina Curceanu
    • 3
  • Andreas Gabriel
    • 1
  • Marcus Huber
    • 1
  • Jan-Åke Larsson
    • 4
  • Pawel Moskal
    • 5
  1. 1.Faculty of PhysicsUniversity of ViennaViennaAustria
  2. 2.Sapienza Università di Roma and INFN Sezione di RomaRomeItaly
  3. 3.Laboratori Nazionali di Frascati dell’INFNFrascatiItaly
  4. 4.Institionen för SystemteknikLinköpings UniversitetLinköpingSweden
  5. 5.Institute of PhysicsJagiellonian UniversityCracowPoland

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