Near threshold K+K− meson-pair production in proton–proton collisions

The near threshold total cross section and angular distributions of K+K− pair production via the reaction pp→ppK+K− have been studied at an excess energy of Q=17 MeV using the COSY-11 facility at the cooler synchrotron COSY. The obtained cross section as well as an upper limit at an excess energy of Q=3 MeV represent the first measurements on the K+K− production in the region of small excess energies where production via the channel pp→ppΦ →ppK+K− is energetically forbidden. The possible influence of a resonant production via intermediate scalar states f0(980) and a0(980) is discussed.