Observation of an Enhancement in p¯p→π+π− and p¯p→K+K− Cross Sections at p¯ Momentum of ∼ 500 MeV/c

Abstract

The reactions $\overline{p}p\to {\pi }^{+}{\pi }^{-}$ and $K^{+}{K}^{-}$ have been studied at 390, 490, 590, 690, and 780 MeV/c. An enhancement of about 150 μb has been observed in the cross sections of both reactions at the same beam momentum of 490 MeV/c. If this structure is interpreted as a meson resonance, it has a mass of 1940 ± 20 MeV and a width of less than 40 MeV.