1. Frascati 2006, Beatrix C. Hiesmayr Testing QM in Particle Physics by Beatrix C. Hiesmayr Institute for Theoretical Physics University of Vienna Austria experimental phenomenological conceptualmathematical aspects

2. Frascati 2006, Beatrix C. Hiesmayr Testing QM in high energy physics Bell inequalities Bell inequalities How to measure entanglement or decoherence? How to measure entanglement or decoherence? “Kaonic” Quantum Erasers “Kaonic” Quantum Erasers “Erasing the Past and Impacting the Future” Bohr’s Complementarity in two-path interferomety Bohr’s Complementarity in two-path interferomety ( kaons are doubleslits given freely by Nature ) Duality in Particle Physics Duality in Particle Physics Bertlmann, Durstberger, Hiesmayr, Phys. Rev. A 68 (2003) 012111. Bertlmann, Grimus, Hiesmayr,Phys. Rev. D 60 (1999) 114032. Bramon,Garbarino, Hiesmayr, Phys. Rev. A 69 (2004) 022112. Hiesmayr, Found. of Phys. Lett. 14 (2001). Bertlmann, Bramon, Garbarino, Hiesmayr, Phys. Lett. A 332, (2004) 355. Bertlmann, Grimus, Hiesmayr, Phys. Lett. A 289 (2001) 21. Bertlmann, Hiesmayr, Phys. Rev. A 63 (2001) 062112. Bramon, Garbarino, Hiesmayr, Phys. Rev. Lett. 92 (2004) 020405. Bramon, Garbarino, Hiesmayr, Phys. Rev. A 68 (2004). 062111 Bramon, Garbarino, Hiesmayr, Eur. J. Phys. C 32 (2004) 377. KEK (Japan) & DA  NE? Aharanov & Zubairy: Science 307:875, 2005

3. Frascati 2006, Beatrix C. Hiesmayr Outline R. Feynman: “The double slit contains the only mystery.” “If there is any place where we have a chance to test the main principles of quantum mechanics in the purest way---does the superposition of amplitudes work or doesn't it?---this is it.” R. Feynman about neutral kaons:

4. Frascati 2006, Beatrix C. Hiesmayr Neutral kaons viewed a little differently: Kaon in time: short-lived statelong-lived state „A kaon is a kind of double slit“ Strangeness: Mass-eigenstates: Feynman diagram Bramon,Garbarino, Hiesmayr, Phys. Rev. A 69 (2004) 022112.

5. Frascati 2006, Beatrix C. Hiesmayr “Erasing the past and impacting the future” 1801 Thomas Young: Photons interfere! Interference lost because photon watched (gain which way info)! Erasing the which way info brings interference back! No wonder Einstein would be confused! 1982 Drühl & Scully:

6. Frascati 2006, Beatrix C. HiesmayrComplementarity The observation of an interference pattern and the adquisition of which-way information are mutually exclusive. Quantum systems possess properties that are equally real but mutually exclusive!  wave-particle duality Bohr’s principle of complementarity: Interferometric duality:

7. Frascati 2006, Beatrix C. Hiesmayr Quantitative complementarity How to quantify? Greenberger and Yasin (1988): Englert (1996) predictability= a priori which-way knowledge fringe visibility pure

8. Frascati 2006, Beatrix C. Hiesmayr Complementarity for kaons Visibility (“wave-like” property): Intensity: Neutral kaons:

9. Frascati 2006, Beatrix C. Hiesmayr Complementarity for kaons Predictability (“particle-like” property): Visibility (“wave-like” property): Bohr’s complementarity relation:

10. Frascati 2006, Beatrix C. HiesmayrComplementary Quantitative complementarity in two-path interferometry: 1.Double–slit-like experiments 2.Particle oscillations 3.Scattering of identical particles unified formalism in terms of ``complementarity´´

11. Frascati 2006, Beatrix C. Hiesmayr Quantum eraser for kaons? Ou, Wang, Zou & Mandel 1990 Zou, Wang & Mandel 1991 Herzog, Kwiat, Weinfurter & Zeilinger 1995 Kwiat, Steinberg & Chiao 1992 Tsegaye and Björk 2000 Walborn, Terra Cunha, Padua & Moken 2002 Kim, Yu, Kulik, Shih & Scully 2000 Tifonov, Björk, Sönderholm & Tsegaye 2002 Atoms: Dürr, Rempe 2000 Entangled photons: Scully, Drühl 1982: gedanken experiment concerning the possibility to erase information contained in quantum states Experiments:

12. Frascati 2006, Beatrix C. Hiesmayr Experiment: Herzog et al. second passage first passage normalized to surviving kaon pairs

13. Frascati 2006, Beatrix C. Hiesmayr Experiment: Kim et al.  choice to show which way info or not is partially active!

14. Frascati 2006, Beatrix C. Hiesmayr Measurements: “Active” measurement: Strong interactions: K 0 +p   K + +n K 0 +p   +   K 0 +n   K - +p,  +   “Passive” measurement: Semileptonic decay modes  Q=  S: K 0 (sd)     (ud)+l + + l K 0 (sd)    (ud)+l - + l “Active” measurement: Free propagation: any decay mode observed before t+4.8  S are identified as K S at time t Misidentification: few parts in 10 -3 ! “Passive” measurement: Sensitive to the decay modes: 2  ’s are identified as K S 3  ’s are identified as K L Misidentification: few parts in 10 -3 ! Strangeness basis: Lifetime basis:

15. Frascati 2006, Beatrix C. Hiesmayr (A) Active Eraser with active measurements object system meter system S, t l S, t r 0 T, t r 0 left (object)right (meter) 1.Setup (matter block remove): active S active T 2.Setup (matter block inserted): active S active S source

16. Frascati 2006, Beatrix C. Hiesmayr (B) Partially active eraser with active measurements object system meter system S, t l S, t r 0 left (object)right (meter) active S active T, active S source T  partially active choice due to instability of kaon

17. Frascati 2006, Beatrix C. Hiesmayr (C) Passive eraser with passive measurements object system meter system S, t l S left (object)right (meter) active S passive T, passive S source T T

18. Frascati 2006, Beatrix C. Hiesmayr (D) Passive eraser with passive measurements left (??object??)right (??meter??) passive T, passive S TTS S

19. Frascati 2006, Beatrix C. Hiesmayr Summary of “kaonic” eraser remarkably all these QE options lead to the same probabilities! this is even true regardless the temporal ordering demonstrates nicely the very nature of QE: sorting events  Up to our opinion: It should be possible to test it at DA  NE!

20. Frascati 2006, Beatrix C. Hiesmayr Questions to the experimenters: Are active measurements possible? Which initial entangled states can be produced (besides the antisymmetric Bell state)? Can the CP state |K 1 > be somehow measured? Or can another superposition be measured? Can the long lived state |K L > be “boosted”?