摘要
The A（1405） resonance emerges in the meson-baryon scattering amplitude with the strangeness S = - 1 and isospin I = 0. It is the archetype of what is called a dynamically generated resonance, as pioneered by Dalitz and Tuan [1]. The most powerful and systematic approach for the low-energy regime of the strong interactions is chiral perturbation theory （ChPT）, see e.g. Ref. 2. A perturbative calculation is, however, not applicable to this sector because of the existence of the A（1405） just below the KN threshold. In this case, ChPT has to be combined with a non-perturbative resummation technique, just as in the case of the nuclear forces. By solving the Lippmann- Schwinger equation with the interaction kernel determined by ChPT and using a particular regularization, in Ref. 3 a successful description of the low-energy K-p scattering data as well as the mass distribution of the A（1405） was achieved （for further developments, see Ref. 4 and references therein）.
The A（1405） resonance emerges in the meson-baryon scattering amplitude with the strangeness S = - 1 and isospin I = 0. It is the archetype of what is called a dynamically generated resonance, as pioneered by Dalitz and Tuan [1]. The most powerful and systematic approach for the low-energy regime of the strong interactions is chiral perturbation theory （ChPT）, see e.g. Ref. 2. A perturbative calculation is, however, not applicable to this sector because of the existence of the A（1405） just below the KN threshold. In this case, ChPT has to be combined with a non-perturbative resummation technique, just as in the case of the nuclear forces. By solving the Lippmann- Schwinger equation with the interaction kernel determined by ChPT and using a particular regularization, in Ref. 3 a successful description of the low-energy K-p scattering data as well as the mass distribution of the A（1405） was achieved （for further developments, see Ref. 4 and references therein）.
