$\pi \mathrm{\Lambda }$ scattering phase shifts and CP violation in $\mathrm{\Xi }\to \pi \mathrm{\Lambda }$ decay

CP-violating signals in weak $\mathrm{\Xi }\to \pi \mathrm{\Lambda }$ decay require the knowledge of $\pi \mathrm{\Lambda }$ $S$- and $P$-wave scattering phases at $m_{\mathrm{\Xi }}$ center-of-mass energy. We have calculated these phases in baryon chiral perturbation theory with the ground-state $\mathrm{\Sigma }$ in $s$ and $u$ channels and ${\frac{3}{2}}^{+}$ $\mathrm{\Sigma }(1385)$ in the $u$ channel. We do not treat the baryons as heavy. We find ${\delta }_S={1.2}^{\circ }$ and ${\delta}_{P} = -{1.7}^{\circ}$withthecentralvalueofthestrongcouplingparameter$D$. We also investigate the variation of the scattering phases as functions of the parameter $D$. We compare this result with previous calculations, and discuss its relevance to CP-asymmetry parameters.