The uncertainties of background contributions to J = 0 partial wave πK scattering phase shifts are carefully studied. We firstly point out that the circular cuts exhibit different characters in S1/1 and S3/2 waves. W...The uncertainties of background contributions to J = 0 partial wave πK scattering phase shifts are carefully studied. We firstly point out that the circular cuts exhibit different characters in S1/1 and S3/2 waves. While the former contributes negatively to the scattering length parameter, the latter contributes positively, i.e., has a wrong sign. This fact indicates that short range force contribu tions to the phase shift are non-negligible in the exotic channel. Nevertheless, it is verified that the κ pole will be affected only slightly with respect to the theoretical uncertainty in estimating the left hand cut contributions.展开更多
The low-energy S-wave πN and KN scatterings are studied by using the K-matrix approach within the meson exchange framework. The t-channel meson exchanges, especially ρ and σ exchanges, are found to play a very impo...The low-energy S-wave πN and KN scatterings are studied by using the K-matrix approach within the meson exchange framework. The t-channel meson exchanges, especially ρ and σ exchanges, are found to play a very important role in these two processes. The t-channel p exchange determines the isospin structure of the scattering amplitudes, it gives attractive force in the low isospin state but repulsive force in the high isospin state. The t-channel σ exchange gives a very large contribution in these two processes, while it is negligible in meson-meson S-wave scatterings.展开更多
基金The project supported in part by National Natural Science Foundations of China under Grant Nos. 10575002, 10421503, and 10491306.Acknowledgments It is a pleasure to thank Prof. Han-Qing Zheng for valuable discussions and a careful reading of the manuscript.
文摘The uncertainties of background contributions to J = 0 partial wave πK scattering phase shifts are carefully studied. We firstly point out that the circular cuts exhibit different characters in S1/1 and S3/2 waves. While the former contributes negatively to the scattering length parameter, the latter contributes positively, i.e., has a wrong sign. This fact indicates that short range force contribu tions to the phase shift are non-negligible in the exotic channel. Nevertheless, it is verified that the κ pole will be affected only slightly with respect to the theoretical uncertainty in estimating the left hand cut contributions.
基金National Natural Science Foundation of China (10435080, 10521003)Chinese Academy of Sciences (KJCX3-SYW-N2)
文摘The low-energy S-wave πN and KN scatterings are studied by using the K-matrix approach within the meson exchange framework. The t-channel meson exchanges, especially ρ and σ exchanges, are found to play a very important role in these two processes. The t-channel p exchange determines the isospin structure of the scattering amplitudes, it gives attractive force in the low isospin state but repulsive force in the high isospin state. The t-channel σ exchange gives a very large contribution in these two processes, while it is negligible in meson-meson S-wave scatterings.
