Study of the Reactionπ++p→Σ++K+near Threshold

Abstract

The reaction ${\pi }^{+}+p\to {\Sigma }^{+}+K^{+}$ has been studied in the momentum range 1037 through 1065 MeV/c with specific regard to the determination of $s$- and $p$-wave amplitudes. If we represent these amplitudes near threshold by $S_{\frac{1}{2}}=a_0{k}^{\frac{1}{2}}$, $P_{\frac{1}{2}}+2\mathrm{}{P}_{\frac{3}{2}}=b_0{k}^{\frac{3}{2}}{e}^{i{\chi }_b}$, and $P_{\frac{3}{2}}-P_{\frac{1}{2}}=c_0{k}^{\frac{3}{2}}{e}^{i{\chi }_c}$, the following results have been obtained from an analysis based on 274 events: ${a_0}^2=(3.31\mathrm{}\pm 0.87)\times {10}^{-5\mathrm{}}$ mb/sr-MeV/c, $\frac{b_0}{a_0}=0.0075\mathrm{}\pm 0.0026$, $\frac{c_0}{a_0}=-0.0062\mathrm{}\pm 0.0023$, ${\chi }_b=52.1\mathrm{}\pm 8.0$ deg, ${\chi }_c=80.8\mathrm{}\pm 27.2$ deg. An alternative set of solutions exists for ${\chi }_b=-52.1\mathrm{}$ deg and ${\chi }_c=99.2\mathrm{}$ deg.