The Constraining Effect of Isospin Filtering Processes in Low Energy Meson-Baryon Interactions

摘要

Motivated by the recent precise SIDDHARTA measurement of the energy shift and width of kaonic hydrogen, we have revisited the theoretical study of the meson-baryon interaction in the S = -1 sector, employing a chiral SU(3) lagrangian up to next-to-leading order (NLO) and implementing unitarization in coupled channels. The parameters of the model have been fitted to a large set of experimental data, paying attention to processes that are especially sensitive to the NLO terms, such as the K~- p → K~(+Ξ-),K~(0Ξ0) reactions. Explicit resonant terms have been included to explore their effects on the stability of the low-energy constants and the data description. We have also studied the role of new single isospin reactions and have found them to provide more homogeneous and reliable NLO parameters. We conclude that additional isospin filtering processes, like the K_L~0p → K~(+Ξ0) reaction that could be measured at the proposed secondary K_L~0 beam at Jlab, would put valuable constraints on the chiral models describing the S = -1 meson-baryon interaction.