1 / 29

60 Co and the Death of Parity

60 Co and the Death of Parity. Time Line. 1949: - Puzzle. Tau-Theta Puzzle. Tau-Theta Puzzle. •  + + + + - •  + + 0. Tau-Theta Puzzle. •  + + + + - •  + + 0 •P  =-1. Tau-Theta Puzzle. •  + + + + - •  + + 0 •P  =-1 •P  ≠P . Time Line.

Rita
Download Presentation

60 Co and the Death of Parity

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 60Co and the Death of Parity

  2. Time Line 1949: - Puzzle

  3. Tau-Theta Puzzle

  4. Tau-Theta Puzzle •++++- •++0

  5. Tau-Theta Puzzle •++++- •++0 •P=-1

  6. Tau-Theta Puzzle •++++- •++0 •P=-1 •P≠P

  7. Time Line 1949: - Puzzle 1956: Lee and Yang

  8. Lee and Yang

  9. Lee and Yang •What if = ?

  10. Lee and Yang •What if = ? •Plenty of Evidence of P Conservation for Strong Force and EM

  11. Lee and Yang •What if = ? •Plenty of Evidence of P Conservation for Strong Force and EM •No Experimental Tests of P Conservation for Weak Force

  12. Lee and Yang •What if = ? •Plenty of Evidence of P Conservation for Strong Force and EM •No Experimental Tests of P Conservation for Weak Force •Does / Decay Violate Parity?

  13. Parity Violation

  14. Parity Violation

  15. Parity Violation Need a correlation between a vector (emission) and a pseudovector (spin)

  16. Time Line 1949: - Puzzle 1956: Lee and Yang 1957: 60Co  Decay

  17.  Decay Parity Violation Problems: Alignment of Nuclear Spin Measurement of Spin Alignment Cryogenics Solution: 60Co

  18. Reasons to Use 60Co Strong Magnetic Moment  Easy to Polarize • Emission Prefers Spin Axis  Measurement of Polarization Incorporation in a Crystal  Adiabatic Demagnetization to <1°K

  19. Co doped [2Ce(NO3)3•3Mg(NO3)2 •24H2O] cooled to .01°K

  20. Time Line 1949: - Puzzle 1956: Lee and Yang 1957: 60Co  Decay 1957: --e Channel

  21. --e Parity Violation Nevis Lab: 400MeV p+ Cyclotron p+ collision ++e+ Direction of + beam defines spin axis Look for asymmetries in spin alignment

  22. Publications: CS Wu, et al “Experimental test of parity conservation in beta decay.” Physical review, 1957 LM Lederman, RM Garwin, M Weinrich “Observations of the failure of conservation of parity and charge conjugation in meson decays: The magnetic moment of the free muon.” Physical review, 1957

  23. Conclusions:

  24. Conclusions: Don’t share paradigm shifting results until you’re ready to publish!

  25. Credit for images goes to: George L. Trigg. Landmark Experiments in Twentieth Century Physics. New York: Crane, Russak & co., 1975 C.S. Wu and S.A. Moszkowski. Beta Decay. Hoboken:John Wiley & Sons, 1966 Leon Lederman. The God Particle. Boston: Houghton Mifflin co., 1993

More Related