Studies of Nuclear Medium Effects with Kaons

With intense and K beams at the AGS, one of the central goals in the realm of spectroscopy and dynamics is the investigation of how strange and non-strange baryon resonances propagate in the nuclear medium. The modifications of the mass and width of these objects tells us about the interaction of unstable particles with nucleons via the resonance-nucleus optical potential. The and are prime candidates for such studies, since their free-space decay widths are of the order of ~ 15 and 35 MeV, respectively, much less than the width of the in the non-strange sector. There is also the attractive possibility of studying baryon resonances which couple strongly to the channel, in particular the and , with the goal of better determining the decay branching ratio and providing a challenging constraint for quark modelers. Along this line, an interesting example of medium effects, representing an ongoing theoretical challenge, has appeared in the K+ total cross section and quasi-free scattering data taken on a range of nuclei at the AGS.