Antiproton-Proton Annihilation into Charged Pion and Kaon Pairs from 0.7 to 2.4 GeV/c

A counter-spark-chamber experiment has been performed to measure the annihilation reactions $\overline{p} p$ ${\pi }^{+} \pi$ and $\overline{p} p$ $K^{+} K$ in the energy region 0.7-2.4 GeV/c. The angular region covered in the experiment was $0.65\le cos{\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}\le 1.0$. The data were taken in order to study heavy bosons (mass greater than two nucleons) that might couple to the $\overline{p} p$ system. Our data have been combined with data from a previous BNL-Caltech experiment to give complete folded angular distributions and total cross sections for these reactions at 12 incident momenta. The folded two-pion annihilation data have been fitted by a simple Breit-Wigner resonance model in order to explore possible resonance behavior. The extreme-angle data have been interpreted in terms of particle exchanges, and through crossing symmetry comparisons are made with backward $\pi p$ and $Kp$ scattering.