Proton induced $K^+$ production and the $s\bar{s}$ content of the proton
  We investigate the exclusive proton-induced $K^+$ production near the kaon threshold. Compared are two models: a meson-exchange model, which includes $\pi$, \rho$, $K$ and $K^\ast$ exchange, together with the dominant baryon resonances, and a quark-gluon model, where momentum sharing is provided via the exchange of two gluons. Based on covariant bound state wave functions for the meson and the baryons - which we treat as quark-diquark objects - first results for the $pp\to p\Lambda K^+$ total cross section are presented for both models. 
Frieder Kleefeld, Fernando Pilotto and Manfred Dillig