1. Dr Mark Hadley Parity Violation: The Biggest Scientific Blunder of the 20th Century?

2. Mark Hadley Is Nature Symmetrical? We thought so until 1956 !! A Major change in our view of space and time 1.Round Earth 2.Heliocentric view of Universe 3.Special Relativity (time is not absolute) 4.General relativity (spacetime is curved) 5.Big bang – Universe finite in space and time 6.Expanding Universe (time asymmetry)

3. Mark Hadley Plan Parity violation – the conventional view My interest Review of Parity conservation –Mechanics –Electromagnetism –Weak Interactions An alternative view –Parity is Conserved !!

4. Mark Hadley Space Inversion Inversion = reflection + 180° rotation Axial or Pseudo vector

5. Mark Hadley Effect of Parity - momentum BeforeAfter The Parity Operator gives the transformation due an inversion of the spatial coordinates

6. Mark Hadley Effect of Parity - spin BeforeAfter

7. Mark Hadley Physical Review October 1956 p254-258 Tsung Dao Lee Chen Ning Yang Parity violation in the weak interactions

8. Start with a symmetrical state 60 Co Look for an asymmetric outcome e-e- 60 Ni + e - +υ e I(θ)dθ = k (1 + αcosθ )sinθdθ θ

9. Mark Hadley Experimentalists Wu Ambler Hayward Hoppes Hudson National Bureau of Standards USA 1956

10. actual result I(θ)dθ = k (1 –v/c cosθ )sinθdθ

11. Mark Hadley Nobel prize winners 1957 Tsung Dao Lee Chen Ning Yang Parity violation in the weak interactions

12. Mark Hadley But not quite so simple……. Is the initial state symmetrical? “We see from this analysis that the logical path from the observed asymmetry to the inferred nonconservation of parity in β decay is considerably more complex than the popular presentations would indicate.” L. E. Ballentine:

13. Mark Hadley A gravitational explanation for quantum theory Aims to explain –QM –Particle spectrum –Fundamental interactions Predictions –No graviton (Gravity waves are just classical waves) –Spin-half –Parity is conserved

14. Mark Hadley Parity is violated - FACT All the books say so. The Nobel Prize Committee say so.

15. Doh !

16. Mark Hadley Explanations using GR Boundary Conditions Common source  

17. Doh !!

18. Mark Hadley Where have they gone wrong? Exactly what has been observed? Exactly what has been violated? What, exactly, is the definition of Parity?

19. Mark Hadley Parity in Newtonian Mechanics F = ma E = ½m v 2 F = m(-a) -F = m (-a) -F = (-m)(-a) F = (-m)(-a) (± )E = ½(± m) v 2 Before After Parity conserved  

20. Mark Hadley P operator is chosen: 1)For simplicity 2)To conserve parity 3)Supported by: Special Relativity: (t-component of the energy momentum 4-vector) General Relativity: Parity in Newtonian Mechanics

21. Magnetic field pointing out e-e- e-e- e-e- e-e- e-e- e-e- Parity in electromagnetism Start with a symmetrical state……

22. Mark Hadley Parity in Electromagnetism F = q(E + v x B) Note: -F = q(-E + -v x (-B)) -F = q(-E + -v x B) -F = -q(E + -v x B) -F = -q(E + -v x (-B)) Before After Parity conserved  

23. Parity on magnetic poles

24. Magnetic field pointing out e-e- e-e- e-e- e-e- e-e- Parity in electromagnetism

25. Magnetic field pointing in e-e- e-e- e-e- e-e- e-e-

26. Mark Hadley Duality Transforamtion The roles of E and B can be reversed by a duality transformation:

27. Parity in Electromagnetism In this order P operator is chosen: 1)To conserve parity 2)For simplicity 3)Supported by the covariant formulation:

28. Mark Hadley Effect of Parity The Parity Operator gives the transformation due an inversion of the spatial coordinates. We do not have a free choice of P operator. What are the transformations in beta decay?

29. Mark Hadley “We see from this analysis that the logical path from the observed asymmetry to the inferred nonconservation of parity in β decay is considerably more complex than the popular presentations would indicate.” L. E. Ballentine: The assumption that the Cobalt nucleous is symmetrical is not only non-trivial - it may well be wrong !

30. What is the mirror image of a Cobalt atom? 60 Co e-e- (not to scale) e-e- 60 Co e+e+ Anti 60 Co

31. Mark Hadley Parity Reverses –Momentum –Lepton number etc. –Charge Unchanged –Spin Is conserved

32. Mark Hadley Conclusions Space Inversion is a symmetry of Nature Parity is conserved The conventional P operator is not conserved.

33. Mark Hadley Just a change of convention? The conventional P operator may be combined with another transformation of degenerate multiplets. (eg particle anti- particle, neutrino flavours) Impacts on unifying theories. “Not merely a matter of convention: on other particles P could have the usual effect.” Weinberg

34. Mark Hadley Parity violation How could they get it so wrong?

35. Mark Hadley How could they get it so wrong? The Parity operation was defined before the experiments were done. –Particles were defined as eigenstates of Parity. –Simplicity of the operator took precendence over conservation - even though QFT required particles and antiparticles to be combined in the same equations. There was no higher theory to appeal to. Watch this space!

36. Mark Hadley Parity is Conserved

37. Mark Hadley Parity Lorentz Boost Eigenvectors of P, H,J 3 with eigenvalues 0,M,σ

38. Mark Hadley CP violation Boundary conditions –Matter dominated Universe T asymmetry (CPT theorem) –Expanding Universe Parity = CP for some particles only! More complicated effects of P on other degeneracies.