KAON VERSUS ANTIKAON PRODUCTION AT SIS ENERGIES

摘要

We analyse the production and propagation of kaons and antikaons in Ni + Ni reactions from 0.8-1.85 GeV/u within a coupled channel transport approach including the channels BE --> K+YN, pi B --> K+Y, BB --> NNK (K) over bar, pi B --> NK(K) over bar, K+B --> K+B, (K) over bar B --> (K) over bar B, YN --> (K) over bar NN, pi pi --> K (K) over bar as well as pi pi Y --> (K) over bar N and (K) over bar N --> pi Y for the antikaon absorption. Whereas the experimental K+ spectra can be reproduced without introducing any self-energies for the mesons in Ni + Ni collisions from 0.8 to 1.8 GeV/u, the K- yield is underestimated by a factor of 5-7 at 1.66 and 1.85 GeV/u. However, introducing density dependent antikaon masses in line with effective chiral Lagrangians, the antikaon spectra can be reasonably well described. [References: 72]