%0 Journal Article %T Azimuthal Emission Patterns of $K^{+}$ and of $ K^{-} $ Mesons in Ni + Ni Collisions near the Strangeness Production Threshold %A V. Zinyuk %A T. I. Kang %A Y. Leifels %A N. Herrmann %A B. Hong %A R. Averbeck %A A. Andronic %A V. Barret %A Z. Basrak %A N. Bastid %A M. L. Benabderrahmane %A M. Berger %A P. Buehler %A M. Cargnelli %A R. £¿aplar %A I. Carevic %A P. Crochet %A I. Deppner %A P. Dupieux %A M. D£¿elalija %A L. Fabbietti %A Z. Fodor %A P. Gasik %A I. Ga£¿pari£¿ %A Y. Grishkin %A O. N. Hartmann %A K. D. Hildenbrand %A J. Kecskemeti %A Y. J. Kim %A M. Kirejczyk %A M. Ki£¿ %A P. Koczon %A R. Kotte %A A. Lebedev %A A. Le F¨¨vre %A J. L. Liu %A X. Lopez %A V. Manko %A J. Marton %A T. Matulewicz %A R. M¨¹nzer %A M. Petrovici %A K. Piasecki %A F. Rami %A A. Reischl %A W. Reisdorf %A M. S. Ryu %A P. Schmidt %A A. Sch¨¹ttauf %A Z. Seres %A B. Sikora %A K. S. Sim %A V. Simion %A K. Siwek- ilczy¨½ska %A V. Smolyankin %A K. Suzuki %A Z. Tyminski %A P. Wagner %A E. Widmann %A K. Wi£¿niewski %A Z. G. Xiao %A I. Yushmanov %A Y. Zhang %A A. Zhilin %A J. Zmeskal %J Physics %D 2014 %I arXiv %R 10.1103/PhysRevC.90.025210 %X Azimuthal emission patterns of $K^\pm$ mesons have been measured in Ni + Ni collisions with the FOPI spectrometer at a beam kinetic energy of 1.91 A GeV. The transverse momentum $p_{T}$ integrated directed and elliptic flow of $K^{+}$ and $K^{-}$ mesons as well as the centrality dependence of $p_{T}$ - differential directed flow of $K^{+}$ mesons are compared to the predictions of HSD and IQMD transport models. The data exhibits different propagation patterns of $K^{+}$ and $K^{-}$ mesons in the compressed and heated nuclear medium and favor the existence of a kaon-nucleon in-medium potential, repulsive for $K^{+}$ mesons and attractive for $K^{-}$ mesons. %U http://arxiv.org/abs/1403.1504v3