A chiral quark-model approach is employed to study theˉ KN scattering at low energies.The processes of Kˉp →Σ 0 π 0,Λπ 0 andˉ K 0 n at P K 800 MeV/c (i.e.the center mass energy W 1.7 GeV) are investigated.The analysis shows that the Λ(1405)S 01 dominates the processes Kˉp →Σ 0 π 0,ˉ K 0 n in the energy region considered here.Around P K 400 MeV/c,the Λ(1520)D 03 is responsible for a strong resonant peak in the cross section of Kˉp →Σ 0 π 0 andˉ K 0 n.To reproduce the data,an unexpectedly large coupling for Λ(1520)D 03 to KN is needed.In contrast,the coupling for Λ(1670)S 01 to KN appears to be weak,which could be due to configuration mixings between Λ(1405)S 01 and Λ(1670)S 01 .By analyzing Kˉ p →Λπ 0,evidences for two low mass S-wave states,Σ(1480)S 11 and Σ(1560)S 11,seem to be available.With these two states,the reaction Kˉp →ˉ K 0 n can also be described well.However,it is difficult to understand the low masses of Σ(1480)S 11 and Σ(1560)S 11 .The s-channel amplitudes for Kˉp →Λπ 0 are also larger than the naive quark model expectations.The non-resonant background contributions,i.e.t-channel and/or u-channel,also play important roles in the explanation of the angular distributions due to amplitude interferences.
A chiral quark-model approach is extended to the study of the KN scattering at low energies. The process of K-p →Σ0π0 at PK 800 MeV/c (i.e. the center mass energy W 1.7 GeV) is investigated. The Λ(1405)S01 dominates the reactions over the energy region considered here. Around PK 400 MeV/c, the Λ(1520)D03 is responsible for a strong resonant peak in the cross section. Our analysis suggests that there exist configuration mixings within the Λ(1405)S01 and Λ(1670)S01 as admixtures of the [70,21,1/2] and [70,28,1/2] configurations. The Λ(1405)S01 is dominated by [70,21,1/2], and Λ(1670)S01 by [70,28,1/2]. The non-resonant background contributions, i.e. u-channel and t-channel, also play important roles in the explanation of the angular distributions due to amplitude interferences.
