Class #5 (Feb. 7) Reading Questions - Particle Physics, Secs. 11-14, Handout pgs. 23-30



1. Explain why the magnetic field vector (H) shown in Fig 11.1 points in the same direction in both the "real world" and the "mirror world".  Vectors of this type are known as "axial" or "pseudo" vectors.  [Hint: how do you create a magnetic field?]  If the magnetic field was parallel to the mirror plane how would the direction in the real and mirror worlds compare?   [Comment: angular momentum is also an axial vector and thus the nuclear spin in this figure has the same behavior as the magnetic field.]


2.  In the Wu beta-decay experiment most of betas are found to be emitted in the direction opposite to the nuclear spin direction.  Explain how this simple result demonstrates that beta-decay violates parity conservation.


3.  In what sense are neutrinos left-handed?  Describe the experiment that first demonstrated this.

     Are there any right-handed neutrinos in the universe?


4. Describe the experiment of Lederman, Schwartz, and Steinberger that provided evidence for the existence of two different types of neutrino.  [Note: The steel shielding used in this experiment came from a dismantled battleship and was 44 feet thick!]


5.  The neutral kaon ... what is it?  Under what conditions is a neutral kaon a "kaon" and when is it a (K1+K2)? What experimental observation motivated the idea of a K1 and K2 particle?


6.  Explain the experiment of Turlay et al. that first demonstrated the violation of CP-symmetry in Kaon decay.  How does this result establish a clear distinction between matter and anti-matter?


