MESIC INTERACTIONS IN VERY LIGHT NUCLEI

Abstract

Publisher Summary This chapter provides an overview of mesic interactions in light nuclei and discusses the scattering, absorption, and production of pions and kaons on systems with nucleon number A=2, 3, or 4, focusing on the processes involving only strongly interacting particles. There are ways in which mesic interactions in the relatively known light nuclei can elucidate meson reaction mechanisms and aid in understanding the heavier nuclei. They can also be turned to good advantage in trying to learn more about the properties of elementary particles. There are a number of features of mesic interaction mechanism for whose study the light nuclei can be useful. The problems with multiple-scattering treatments of meson–nucleus interactions include (1) the unknown off-shell behavior of the meson–nucleon amplitudes, and (2) the double-counting confusion as to whether an exchanged meson is being re-scattered or is trying to mediate the usual nuclear force. Thus, the light nuclei are a natural first testing ground for the legitimacy of multiple-scattering theories. They serve a similar purpose for absorption processes. The chapter also reviews scattering processes, and the pion and kaon interactions in very light nuclei. At large momentum transfer, where double scattering becomes important, the results are very sensitive to the magnitude and phase of the pion–nucleon scattering amplitude that vary in the kinematic region and have sufficient experimental uncertainty associated with them to cover the apparent discrepancy.