60 Co and the Death of Parity. Time Line 1949: - Puzzle.
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Transcript of 60 Co and the Death of Parity. Time Line 1949: - Puzzle.
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
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?
Decay Parity Violation
Problems:
Alignment of Nuclear Spin
Measurement of Spin Alignment
Cryogenics
Solution:60Co
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
--e Parity Violation
Nevis Lab: 400MeV p+ Cyclotron
p+ collision ++e+
Direction of + beam defines spin axis
Look for asymmetries in spin alignment
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