Published by Bryan at January 14, 2015 That is, these two states are reflections of each other, see the figure, The operation of reflection via P13 changes one state into its mirror image. This is exactly the property sort by Yang and Lee to solve the fact that parity is not conserved for the electro-weak force. Using their example, if cobalt atoms undergo beta decay, and you watch it in a mirror, then the magnetic moments are not reflected, and so parity is violated.