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Spooky action at distance also for neutral kaons? by Beatrix C. Hiesmayr University of Vienna 2SGA2746 Projects FWF-P21947N16 and FWF-P23627 Very short history… 1935: Einstein-Podolsky-Rosen-PARADOX ALICE A ALICE BOB a a 1. pair 2. pair 3. pair 4. pair … B A Beatrix C. Hiesmayr B BOB The EPR reality criterion: “If without in any way disturbing a system, one can predict with certainty (i.e. with the probability equal to one) the value of a physical quantity, then there exists an element of physical reality corresponding to this physical quantity.” Quantum Theory is not complete! Very short history… 1935: Einstein-Podolsky-Rosen-PARADOX Hobby: Foundations of QM 1964: John Stuart Bell What are Bell inequalities? No spooky action at distance! realism locality free will* *exerting their independence; totally randomly Local realistic theories: Bell’s locality hypothesis Quantum Mechanics: P ( a , b) P (a , c ) P ( c , b) P (a, b) d ( ) pA (a, ) pB (b, ) with d ( ) 1 inequalities for probabilities always satisfied! QM probabilities may violate the inequalities! Experiment has to decide! Are local realistic theories ruled out? Photons: many experiments, show violations but still loopholes Various ordinary matter systems: show violations but still loopholes !Single! neutrons: show violations but tests different aspects The EPR scenario 1935: Einstein-Podolsky-Rosen-PARADOX Bell state: High Energy Physics 1 2 1 2 H A A K0 12 B 0 ... 1 2 V B B A V A B H B ... spin 1/2 ... photon (polarisation) K 0 ... kaons (K-mesons) A B B A 0 0 B-meson B B B 0 ... A B B A K 0 K 0 1998: CPLEAR collaboration, Physics Letters B 422, 339 Branching ratio depends on hydrogen density 1 2 K0 A K 0 K B 0 K0 A B What are Bell inequalities good for? • Has been proven: quantum cryptography protocols are save if a Bell inequality is violated! • Quantum Computers/Quantum Communication Complexity: Bell inequalities are necessary and sufficient conditions for quantum protocols to beat the classical ones! My goal: to test Bell inequalities for Neutral Kaons ?, H ?, P ? • very difficult, not straightforwardly (even from theoretical point of view)! • but new physics is revealed! • since last year (2012) there is a hope of a doable experiment (with KLOE?, with FLAIR?,…?) Requirements for tests LRT versus QM Requirements for a conclusive proof of the existence of correlation stronger than those explainable by locality and realism/explainable by local resources & shared randomness: (1) “Active ” measurements (opening the possibility for Alice and Bob to choose among alternative setups-> free choice) (2) “Use all information” (test the whole ensemble; decay product states are included this “additional” information cannot be ignored) are not “only” loopholes! Bell inequality for kaons Bertlmann & Hiesmayr,Phys. Rev. A (2001) 0 0 0 0 0 0 0 0 SCHSH ( t a , t b , t c , t d ) : E ( K t a , K t b ) E ( K t a , K t c ) E ( K t d , K t b ) E ( K t a , K t d ) local realistic models 2 S (t n, t m , t n', t m' ; ) 2 0 0 E ( K , ta ; K , t b ) cos m( t a t b ) e ( ta tb ) S Photon 2 2 2.8 Violation! Kaons? S Kaon (ta , tb , tc , td ) 2 NO violation! Summary I If we believe in QM, then there is “spooky action at distance” also for this system at different energy scale, but there exists NO CONCLUSIVE EXPERIMENT so far. Hiesmayr, Eur. Phys. J. C (2007) A violation for observables that can be actively measured can be found, but for an initial non-maximally entangled state. Frascati, Italy Hiesmayr, Domenico, Curceanu, Gabriel, Huber, Larsson, Moskal, Eur. Phys. J. C (2012) New Bell inequality for unstable systems that is experimentally feasible and can be performed with current technology! !?Nonlocality related to a symmetry violation?! Bell inequalities There exists correlations stronger than classical physics allows! CP violation world anti-world CP violation K0 , K 0 2 , CP 1 (C…charge conjugations,P…parity) 3 CP 1 Experiment: 1964 Christensen, Cronin, Fitch and Turlay KS KL 1 2(1| |2 ) 1 2(1| | ) 2 { K1 K 2 } { K 2 K1 } 103 CP violation! Leptonic charge asymmetry: ( K L l l ) ( K L l l ) 3 ( 3 . 27 0 . 12 ) 10 ( K L l l ) ( K L l l ) Why are we living in a matter dominated universe? Bell inequality for kaons Bertlmann & Hiesmayr,Phys. Rev. A (2001) 0 0 0 0 0 0 0 0 SCHSH ( t a , t b , t c , t d ) : E ( K t a , K t b ) E ( K t a , K t c ) E ( K t d , K t b ) E ( K t a , K t d ) local realistic models 2 S (t n, t m , t n', t m' ; ) 2 taking into account the decay property without loosing the conclusiveness Hiesmayr et al., Eur. Phys. J. C (2012) min S ( t n , t m , t n', t m ' ; ) S ( t n , t m , t n', t m ' ; ) max S ( t n , t m , t n', t m ' ; ) SEP SEP • for stable systems gives +/-2 Bell inequality for kaons Bell inequality Bound min S ( t n , t m , t n', t m ' ; ) S ( t n , t m , t n', t m ' ; ) max S ( t n , t m , t n', t m ' ; ) SEP SEP • for stable systems gives +/-2 Bell inequality for kaons sensitive to CP violation !!! Bell inequality Bound Bell inequality Bound B.C. Hiesmayr Revealing Bell’s Nonlocality for Unstable Systems in High Energy Physics Hiesmayr, Domenico, Curceanu, Gabriel, Huber, Larsson, Moskal, Eur. Phys. J. C (2012) Revealing Bell’s Nonlocality for Unstable Systems in High Energy Physics Hiesmayr, Domenico, Curceanu, Gabriel, Huber, Larsson, Moskal, Eur. Phys. J. C (2012) A little history… Drawn by R.A. Bertlmann to the 60th birthday of John Bell What other foundations of QM can be tested? … a lot !! • The kaonic eraser: „Erasing the Past Impacting the Future“ Bramon, Garbarino, Hiesmayr , Phys. Rev. Lett. 92 Aharanov & Zubairy: (2004) Science 307:875, 2005 • Heisenbergs Uncertainty Relation, Bohr‘s complementarity relation, … A. Di Domenico, A. Gabriel, B. C. Hiesmayr, F. Hipp, M. Huber, G. Krizek, K. Mühlbacher, S. Radic, Ch. Spengler and L. Theussl, Found. Of Physics (2011) A. Bramon, G. Garbarino, Hiesmayr Phys. Rev. A 68 (2004). • Test entanglement: Is there decoherence in the system? (->What causes decoherence? CPT violation (string theory), LorentzInvariance, dark matter,…) Nature: Scientific • Collapse Models Reports: Testing Collapse Models with Neutrinos, Mesons and Chiral Molecules Summary Testing Foundations of QM at all energy scales has started! Higher energies reveal different aspects and new physics! To obtain a full picture of entanglement and to reveal its role in our universe all systems have to be considered! Accelerator experiments can add to our understanding of quantum foundations! … experiments ? KLOE, ELENA, FLAIR Thank you for Your attention! www.quantumparticlegroup.at Why do we see no macroscopic superpositions? Is there a border between a quantum and classical world? And if where is it? • SCHRÖDINGER EQUATION: linear, deterministic, reversible • WAVE PACKET REDUCTION (measurement): nonlinear, stochastic, irreversible One solution: COLLAPSE MODELS (Ghirardi-Rimini-Weber,1986) Consequence: QM would be not fundamental assumes a random field filling space Origin? Gravitation (Penrose), Dark matter/energy,…? Can the collapse be measured for flavor oscillations? Donaldi, Bassi, Curceanu, DiDomenico, Hiesmayr, arXiv:1207.6000 Bahrami, Donaldi, Ferialdi, Bassi, Curceanu, DiDomenico, Hiesmayr, submitted K0 1 2 K S KL After a long and cumbersome computation… P( K 0 , t;| K 0 |) 14 e S t e L t 2 e CSLt cos(mt) e (S L )t CSL Can this be measured?? Neutrinos? strength of the collapse m 16 rC3 m02 2 3 2 correlation length This Wednesday and Thursday Programme of the Workshop „Theory Meets Experiment: Finding Proposals Towards Testing Foundational Issues in Particle Physics“ 8:50-9:00 Wednesday (28.11.2012) Opening (Hiesmayr); from 8:30 registration Chairperson: Mavromatos 9:00-9:30 9:30-10:00 10:00-10:30 Possibilities of Foundational Tests with the KLOE Detector: STATUS&FUTURE (speaker: Di Domenico) Possibilities of Foundational Tests at the Facility FLAIR: STATUS&FUTURE (speaker: Grzonka) Possibilities of Foundational Tests with the Hyperon-Antihyperon system: STATUS&FUTURE (speaker: Kupsc) Chairperson: Sponar 11:30-12:00 12:00-12:30 Chairperson: Brukner On the Feasibility of Bell's inequality and Other New Foundational Tests at KLOE-2 (speaker: Di Domenico) Correlations of Decay Times of Entangled Composite Unstable Systems (speaker: Durt) Recent Photon Experiments Testing Local Realism (speaker: Piacentini) Coffee break 10:30-11:00 11:00-11:30 Thursday (29.11.2012) Possibilities of Foundational Tests in Atomic, Nuclear and Subnuclear Systems: STATUS&FUTURE (speaker: Curceanu) Possibilities of Foundational Tests with Neutrons: STATUS&FUTURE (speaker: Klepp) Possibilities of Foundational Tests with Artificially Engineered Systems: STATUS&FUTURE (speaker: Paraoanu) 12:30-13:00 Lunch Break Coffee break Chairperson: Erker Optimal inequalities for state-independent contextuality (speaker: Larsson) Quantum Frameness for Charge-Parity-Time Reversal Symmetry (speaker: Skotiniotis) Simulating Relativistic Effects of Motion with Superconducting Circuits (speaker: Friis) Towards Relativistic Quantum Technologies (speaker: Bruschi) Lunch Break 12:30-15:00 Meeting in Small Groups CPT in the Early Universe and the Observed Baryon Asymmetry (speaker: Mavromatos) Geometrodynamics: the Kaluza-Klein Compactification and the Quantum Meeting in Small Groups Nonlocality (speaker: De Martini) Chairperson: Bertlmann 15:00-15:30 15:30-16:00 Coffee Break 16:00-16:30 Chairperson: Larsson 16:30-17:00 Is the Compton Frequency a Particle Identification mark? (speaker: Rauch) Coffee Break Moderated discussions: (Moderator: Curceanu) Reports from the Small Groups Closing An experiment for kaons How good do these two data points verify the quantum mechanical interference term? Is the Schrödinger-Furry hypothesis really ruled out? Is there decoherence in the 0 0 0 0 P ( K , t ; K , t ) P ( K , t ; K , tr ) QM system? Loss Aof (entanglement? l r l t ) Traces of quantum gravity, CPT cos(mt ) violations,… cosh( 2 t ) Spontaneous factorization of the wave function Schrödinger-Furry Hypothesis: ( 1) | |K Sl |K L r |K L l |K 50% Sr 50% | K S | K L l |K L |K S r l P ( f1 , tl ; f 2 , tr ) 1 2 2 (1 ) Re *1 2 2 Observable: 2 r 0 0 0 P ( K , t ; K , t ) P ( K , t ; K , tr ) cos(mt ) QM l r l A (tl , tr ) cosh( 2 t ) 0 A (t ) A (t ) (1 ) QM CPLEAR-experiment (1998): 16 0.1300..15 Bertlmann, Grimus and Hiesmayr, Phys. Rev. D, 60, 114032 (1999) Spontaneous factorization of the wave function Schrödinger-Furry Hypothesis ( 1): | K 0 l K 0 K r l K0 l 50% 0 |K 0 |K 0 r 50% 0 |K |K 0 l r r P ( f1 , tl ; f 2 , tr ) 1 2 2 (1 ) Re *1 2 2 A 0 K ,K 0 (t l , t r ) 2 cos(mt ) 12 (cos(mt ) cos(m(t l t r )) cosh(12 t ) 12 (cosh(12 t ) cosh(12 (t l t r )) CPLEAR-experiment (1998): 67 K , K 0.4100..57 0 0 Bertlmann, Grimus and Hiesmayr, Phys. Rev. D, 60, 114032 (1999) Testing entanglement/decoherence interaction in KS,KL Bertlmann, Grimus, Hiesmayr, Phys.Rev. D (1999) KS K L interaction in K0,K0: 0.16 0.13 0.15 K0 K 0 0.4 0.7 Different observable! KLOE Coll., Phys. Lett. B (2006) DiDomenico (2009) KS KL KS KL 0.018 0.040stat 0.07syst 0.003 0.018stat 0.006syst K0 K 0 (0.10 0.21stat 0.04syst ) 105 (1.4 9.5stat 3.8syst ) 107 But (t)=1-e-t? B-mesons: A.Go, BELLE, PRL (2008) 0 K0 K BH BL 0.029 0.057 B.D. Yabsley (2008) arXiv:0810.1822 (D-mesons) PhD, Gerald Richter, HEPHY 2007 “Erasing the past and impacting the future” The quantum eraser 1801 Thomas Young: Photons interfere! Interference lost because photon watched (gain which way info)! 1982 Drühl & Scully: Erasing the which way info brings interference back! No wonder Einstein would be confused! Bell inequality for unstable systems 0 0 0 0 0 0 0 0 S ( t n , t m , t n' , t m ' ; ) E ( K t n , K t m ) E ( K t n , K t m ' ) E ( K t n' , K t m ) E ( K t n' , K t m ' ) 2 S (t n, t m , t n', t m' ; ) 2 Assumption: time evolution (exponential decay) of single kaons is correctly described by QM Experiment: Control over single and joint probabilities ! min S ( t n , t m , t n', t m ' ; ) S ( t n , t m , t n', t m ' ; ) max S ( t n , t m , t n', t m ' ; ) SEP SEP • for stable systems gives +/-2 Frascati, Italy Crash course on neutral kaons: Strangeness: S K 0 K 0 S K 0 K 0 Mass-eigenstates: K , K S L K0 1 2 K S K (t ) „A kaon is a kind of double slit“ Bramon, Garbarino, H., PRA (2004) Kaon in time: 0 KL short-lived state 1 2 e S 2 t imS t Feynman diagram KS e long-lived state L t imL t 2 KL S 1010 1s ...decay width of K S L 1 / 600 S ...decay width of K L m m L m S 0.5 S ...mass difference Univ. of Vienna 2011, Beatrix C. Hiesmayr Loopholes “Detection Loophole”: if not all pairs are measured or if some are misidentified due to imperfections of the detectors, Nature could still be local since some information is missing (“fair sampling assumption”). not closed! …but full control over single and joint probabilities! “Locality Loophole”: measurements of Alice and Bob have to be space-like separated, thus avoiding any possible exchange of subluminal signals about the measurement choices of Alice and Bob Could be closed with enough money… Advantages: one knows essentially with 100% probability that in case a neutral kaon is reconstructed it can only come from an entangled pair. In addition, on average only one entangled pair is generated per event. Generalized Bell inequality for kaons local realistic theories SCHSH (kn , km , kn' , km ' ; ta , tb , tc , td ) E ( kn , t a ; k m , t b ) E ( k n , t a ; k m ' , t c ) E ( k n ' , t d ; k m , t b ) E ( k n ' , t d ; k m ' , t c ) 2 II. Vary in time: kn km k n' k m ' K 0 1 2 0 K0 A K K B 0 K0 A B 0 E ( K , t a ; K , t b ) cos( t a t b ) e ( ta tb ) S Photon 2 2 2.8 Violation! Kaons? 0 Hiesmayr, Eur. Phys. J. C (2007) maxS Kaon (ta , tb , tc , td ) 2.001 Violation! But too small ..