Chiral dynamics of kaon-nucleon interactions, revisited

Abstract

TheKN system close to threshold is analyzed in view of the new accurate DEAR kaonic hydrogen data. The calculations are performed using chiral SU(3) effective field theory in combination with non-perturbative schemes based on coupled channels. Several variants of such approaches are compared with experimental data and the differences in the results are discussed. Coulomb and isospin breaking effects turn out to be important and are both taken into account. The pole structure of the Λ(1405) resonance close to theKN threshold is critically examined.

J/ψNinteractions revisited andΛb0→Xiao1 2017Phys. Rev. D15090View full textAdd to dashboardCite

“…We find that these extra unphysical (sharp) peaks come from the contributions of the unphysical subthreshold effects in the u-channel as discussed in Ref. [44], which appear at some certain energies, e.g., 4258, 4385, and 4457 MeV in the DΣ c , D Ã Σ c , and D Ã Σ Ã c channels, respectively, seen in Fig. 3 (see more discussions in the next section).…”

“…[43][44][45][46][47][48][49][50][51][52][53], there is a factor −2 ffiffiffiffiffiffiffiffiffiffiffiffi…”

“…One step further, up to next-to-leading-order contributions from the Lagrangian, also including the s-and u-channel diagrams of the leading order contributions, the KN interactions and the Λð1405Þ resonance are investigated again in Refs. [44,45] with the analysis of the new experimental data. Along the same line, the improved analyses are done in Refs.…”

The Role of High Spin Hyperon Resonances in the Ξ Production Meson-Baryon Reactions

“…The key ingredient of the proposed scheme is an interaction kernel taken from the chiral Lagrangian. Nowadays the aim for precision and the extension of the approach to higher energies has motivated the introduction of the next-to-leading order (NLO) terms of the chiral Lagrangian, and new fits to experimental data have been performed to determine the parameters of the higher order chiral potential [4][5][6][7][8].…”

“…We would like to stress that the Chiral Lagrangian at NLO is known already for a long time, see Refs. [4][5][6], and the corresponding calculations are not so difficult. It's the large number of the NLO parameters, which were rather purely constrained, what was limiting the practical use of NLO chiral terms.…”