Azimuthal Emission Patterns of $K^_s16$ and of $ K^- $ Mesons in Ni _s16 Ni Collisions near the Strangeness Production Threshold
Keywords
strangeness: production | threshold: production | heavy ion: scattering | nickel | transverse momentum dependence | transport theory | nuclear matter | elliptic flow | K: hadroproduction | FOPI | K_s16: particle flow | K-: particle flow | rapidity dependence | impact parameter: dependence | K nucleon: potential | experimental results | Darmstadt SIS | 1.91 GeV/nucleon
Abstract
Azimuthal emission patterns of K± mesons have been measured in Ni _s16 Ni collisions with the FOPI spectrometer at a beam kinetic energy of 1.91 A GeV. The transverse momentum pT integrated directed and elliptic flow of K_s16 and K_s13_s178722_s19 mesons as well as the centrality dependence of pT - differential directed flow of K_s16 mesons are compared to the predictions of HSD and IQMD transport models. The data exhibits different propagation patterns of K_s16 and K_s13_s178722_s19 mesons in the compressed and heated nuclear medium and favor the existence of a kaon-nucleon in-medium potential, repulsive for K_s16 mesons and attractive for K_s13_s178722_s19 mesons.
