$K^{+}$ and $K^{-}$ potentials in hadronic matter can be observed
  We aim to show that K+ and K- spectra at low transverse momentum measured in light symmetric systems at around 2AGeV depend strongly on the K potential. The ratio of the spectra can allow therefore for a direct determination of the strength of the K+ as well as that of the K- potential in a hadronic environment. 
Aman D. Sood, Ch. Hartnack, and J\"org Aichelin
nucl-th