The differential cross sections for $K_L^{0}p\to K_S^{0}p$ scattering are presented in several momentum intervals between $1 \mathrm{and} 10 \frac{\mathrm{GeV}}{c}$. The data are strongly peaked in the forward direction, characteristic of a large $s$-channel helicity-nonflip scattering amplitude in this reaction, and a distinct break in the differential cross section occurs at $\mathrm{}\left|t\right|=0.3\mathrm{}$ Ge${\mathrm{V}}^2$. The phase of the forward scattering amplitude, $\phi$, is consistent with being independent of momentum. The average value of the phase, $\phi =-133.9\mathrm{}\pm {4.0}^{\circ }$, corresponds to a Regge trajectory $\alpha \mathrm{}\left(0\right)=0.49\mathrm{}\pm 0.05$ in agreement with the canonical $\rho$, ${\omega }^0$ Regge intercept, $\alpha \mathrm{}\left(0\right)\mathrm{}\sim 0.5$. However, this result disagrees with the Regge trajectory determined from the energy dependence of the forward cross section, $\alpha \mathrm{}\left(0\right)=0.30\mathrm{}\pm 0.03$, indicating a breaking of the Regge phase-energy relation. Comparisons of $K_L^{0}p\to K_S^{0}p$ and ${\pi }^{-}p\to {\pi }^{0}n$ scattering data reveal substantial differences in the energy dependence of the differential cross sections. Comparisons to $\mathrm{KN}$ charge-exchange data then suggest that direct-channel (absorption) effects may explain the differences in $\pi N$ and $\mathrm{KN}$ channels.

• Received 5 November 1973

DOI:https://doi.org/10.1103/PhysRevD.9.1939