TRANSVERSE MASS SPECTRA AND RAPIDITY DISTRIBUTIONS OF K+ IN NI–NI COLLISIONS AT 1.93 A GeV

In heavy-ion collisions, the production of kaon at intermediate energies provides a sensitive probe to study the in-medium properties of hadrons. Properties of kaons in dense hadronic matter are important for a better understanding of both the possible restoration of chiral symmetry in dense hadronic matter and the properties of nuclear matter at high densities. In this paper, the in-medium effects and nuclear equation of state (EOS) are studied by analyzing the transverse mass spectra and rapidity distributions of the produced K+ mesons in ${}_{28}^{58}{\rm Ni} + {}_{28}^{58}{\rm Ni}$ collisions at 1.93 A GeV using the quantum molecular dynamics (QMD) model. The work reveals that the KaoS data favor a repulsive in-medium K+N potential (its value at saturation density ρ0 is (Uk(ρ0) ≈30 MeV). It is also found that the transverse mass spectra and rapidity distributions of K+ mesons are sensitive to the nuclear EOS.