Starting with the operator hy, work out the result of evolution of the 1-2, 1-3 and 2-3

Question:

Starting with the operator hy, work out the result of evolution of the 1-2, 1-3 and 2-3 couplings for a time t. Comment on the operators you obtain and the trigonometric factors associated with each.
Draw up a 'tree diagram', of the type shown in Fig. 10.2 on page 324, which represents the results of your calculation.