Antikaon production in proton-nucleus reactions and the K− properties in nuclear matter

Abstract

We calculate the momentum-dependent potentials for K + and K − mesons in a dispersion approach at nuclear density ϱ 0 using the information from the vacuum K + N and K − N scattering amplitudes, however, leaving out the resonance contributions for the in-medium analysis. Whereas the K + potential is found to be repulsive (≈ + 25 MeV) and to show only a moderate momentum dependence, the K − self-energy at normal nuclear matter density turns out to be ≈ − 140 ± 25 MeV at zero momentum roughly in line with K − atomic data, however, decreases rapidly in magnitude for higher momenta. The antikaon production in p + A reactions is calculated within a coupled channel transport approach and compared to the data at KEK including different assumptions for the antikaon potentials. Furthermore, detailed predictions are made for p+ 12C and p+ 207Pb reactions at 2.5 GeV in order to determine the momentum-dependent antikaon potential experimentally.