Direct-channel interference in anti NN → K anti K at low energy and meson towers

The strong suppression of the cross section for the low-energy reaction p̄p→K_S⁰K_S⁰ as compared to p̄p→K_S⁰K_L⁰ and p̄p→K⁺K⁻ is explained as being due to the direct-channel excitation of two massive C=+1 boson resonances with I=1 and I=0, respectively. It is thus suggested that two $J^P=2^{+}$ states with masses below 2.0 GeV and with approximately equal couplings to the N̄N and KK̄ systems, and produced in phase, provide a "natural" explanation of the data. Above 1.2 GeV/c the interference effects appear to disappear and possibly a new physical mechanism for KK̄ production is observed.