In the ${{\mathit B}_{{{s}}}^{0}}$ mixing, propagating mass eigenstates can be written as

$\vert{}{{\mathit B}_{{{sL}}}}\rangle{}$

${}\propto$ p $\sqrt {1 − {{\mathit \xi}} }$ $\vert{}{{\mathit B}_{{{s}}}^{0}}\rangle{}$ + q $\sqrt {1+{{\mathit \xi}} }$ $\vert{}{{\overline{\mathit B}}_{{{s}}}^{0}}\rangle{}$

$\vert{}{{\mathit B}_{{{sH}}}}\rangle{}$

${}\propto$ p $\sqrt {1+{{\mathit \xi}} }$ $\vert{}{{\mathit B}_{{{s}}}^{0}}\rangle{}$ $−$ q $\sqrt {1−{{\mathit \xi}} }$ $\vert{}{{\overline{\mathit B}}_{{{s}}}^{0}}\rangle{}$

where parameter ${{\mathit \xi}}$ controls $\mathit CPT$ violation. If ${{\mathit \xi}}$ is zero, then $\mathit CPT$ is conserved. The parameter ${{\mathit \xi}}$ can be written as
${{\mathit \xi}}$ = ${2(M_{11} − M_{22}) − \mathit i ({{\mathit \Gamma}_{{{11}}}} − {{\mathit \Gamma}_{{{22}}}})\over − 2 {{\mathit \Delta}}{\mathit m}_{{{\mathit s}}} + \mathit i{{\mathit \Delta}}{{\mathit \Gamma}_{{{s}}}}}$ $\approx{}{ − 2 {{\mathit \beta}}{}^{{{\mathit \mu}}} {{\mathit \Delta}}{{\mathit a}}_{{{\mathit \mu}}}\over 2 \Delta {\mathit m}_{{{\mathit s}}} − \mathit i {{\mathit \Delta}}{{\mathit \Gamma}_{{{s}}}}}$,
where $\mathit M_{ii}$, ${{\mathit \Gamma}_{{{ii}}}}$, ${{\mathit \Delta}}{\mathit m}_{{{\mathit s}}}$, and ${{\mathit \Delta}}{{\mathit \Gamma}_{{{s}}}}$ are parameters of Hamiltonian governing ${{\mathit B}_{{{s}}}}$ oscillations, ${{\mathit \beta}}{}^{{{\mathit \mu}}}$ is the ${{\mathit B}_{{{s}}}^{0}}$ meson velocity and ${{\mathit \Delta}}{{\mathit a}}_{{{\mathit \mu}}}$ characterizes Lorentz-invariance violation.