Kaonic Annihilations of Antiprotons in Hydrogen at7 BeVc

Results are reported from an analysis of 80 000 pictures of $6.935-\frac{\mathrm{BeV}}{c}$ antiprotons in hydrogen leading to final states of the form $K_1^{}{}_{}{}^0+K_1^{}{}_{}{}^0+m\pi$, $m=0,1,2\mathrm{}\cdots$. Assuming equal probability for the various $K\overline{K}$ charged states, we find the cross section for the reaction $\overline{p}+p\to K+\overline{K}+m\pi$ to be 2.5±0.5 mb. A compilation of annihilation cross sections indicates that the kaonic-annihilation final states constitute approximately 10% of all annihilations from $\sim 1.6-7 \frac{\mathrm{BeV}}{c}$. The production of $K^{*}\mathrm{}\left(1400\right)\mathrm{}$ has been observed, although the formation of other resonances such as $K^{*}\mathrm{}\left(890\right)\mathrm{}$, $\omega$, and $\rho$ is less copious at $7 \frac{\mathrm{BeV}}{c}$ than at $3.7 \frac{\mathrm{BeV}}{c}$. A $K_1^{}{}_{}{}^{0}K_1^{}{}_{}{}^0$ enhancement near threshold is observed similar to that observed at lower-energy annihilation reactions.