Low Q 2 wave - functions of pions and kaons and their parton distribution functions

We study the low Q 2 wave-functions of pions and kaons as an expansion in terms of hadron-like Fock state fluctuations. In this formalism, pion and kaon wave-functions are related one another. Consequently, the knowledge of the pion structure allows the determination of parton distributions in kaons. In addition, we show that the intrinsic (low Q 2) sea of pions and kaons are different due to their different valence quark structure. Finally, we analize the feasibility of a method to extract kaon's parton distribution functions within this approach and compare with available experimental data. At present the only information available on the structure of unstable mesons is on parton distributions functions (pdf) in pions. These pdf are extracted from Drell-Yan (D-Y) dilepton and prompt photon production in pion-nucleon interactions. In principle, the same type of experiments can be used to extract information on parton distributions in kaons by only replacing the pion beam by a kaon one. However, this requires high intensity kaon beams which are not easily attainable in present day experiments. Furthermore, there is an additional difficulty which is inherent to the kaon structure because strange valence quarks in the kaon must anihilate with strange quarks in the target particles. As targets are made of nucleons, and strange quarks are in the sea of them, these s − ¯ s anihilation processes are expected to have a small *