Mixing Angle of ${\Xi }_Q-{\Xi }_Q^{\mathrm{\prime }}$ in Heavy Quark Effective Therory

The Heavy Quark Effective Theory provides a systematic method to estimate a mixing angle of hadron states in a heavy quark, such as the charm quark © and the bottom quark (b). By using this method, the mixing angle of the baryons ${\Xi }_Q-{\Xi }_Q^{\mathrm{\prime }}$ can be estimated. It is found that the mixing angle between ${\Xi }_Q$ and ${\Xi }_Q^{\mathrm{\prime }}$ is given by $\theta_b = 4.51^{\circ} \pm 0.79 ^{\circ}$for$Q = b$caseand$\theta_c = 8.12^{\circ} \pm 0.80 ^{\circ}$for$Q = c$ case.