Perspectives on relativistic quantum chaos

Liang Huang,Ying-Cheng Lai

Figure 7. Definition of the angles. ${\delta }_{i}^{+}=({\theta }_{i}-{\theta }_{i-1})/2$ is the extra phase due to the rotation of the spin, where ‘+’ indicates counterclockwise orientation. Typically, the phase associated with the time reversed reflection, e.g. ${\delta }_{i}^{-}$, from $-{{\boldsymbol{k}}}_{i}$ to $-{{\boldsymbol{k}}}_{i-1}$, would be different from ${\delta }_{i}^{+}$.