SU(3) flavor symmetry considerations for the K¯N coupled channels system

The impact of final-state interaction on the πΣ photoproduction in the Λ(1405) region

“…2 we show the results obtained in [1] at two sample energies, W = 2.0 (left figures) and 2.4 GeV (right figures) considering four different πΣ − KN models that provide the final state rescattering amplitudes f 0+ . The models include the recent version of the Prague amplitudes [8], tagged as P model, and three versions of the Bonn model amplitudes: B2, B4 [4], and BW [9]. First of all, we note that the P model seems to work reasonably well for the π 0 Σ 0 and π + Σ − cross sections at the c.m.…”

A possible interpretation of Λ baryon spectrum with pentaquark components

“…The Λ (1405) resonance, since discovered in the πΣ invariant mass spectrum [24] in 1960s has been an interesting state in the hyperon spectrum, the nature of the resonance is still under debate. Λ(1405) was first generated dynamically as a NK ¯quasi-bound molecular state [25,26], then followed a large number of studies in chiral unitary approach (ChUA) [27][28][29][30][31] and other chiral dynamics on this resonance [32][33][34][35][36][37][38][39][40][41][42][43][44]. By solving the coupled channel Lippmann-Schwinger equation with a chiral meson-baryon Lagrangian at the next-to-leading order, the Λ(1405) resonance as a quasi-bound state of NK ¯described the low-energy K − p scattering data well [32].…”

“…New fits including the CLAS photoproduction data were carried out in the works [29][30][31]39] and the origin of two poles of Λ(1405)1/2 − were discussed as well. In recent years, the first highmass pole of Λ(1405)1/2 − was shown to be mainly a KN ¯molecular, the second pole was interpreted as a composite state of mainly πΣ with tiny component KN ¯in [40,41,44], and the influence of SU(3) flavor symmetry was analyzed in the last work [44]. Exotic configurations for Λ(1405) have also been proposed, such as a mixed pentaquark and three-quark state [47,48], a hybrid baryon [49], a mixed strange hybrid/three-quark baryon [50] which all applied the method of the QCD sum rule.…”

On Lowest Lying $\frac{1}{2}^-$ Octet Baryons

“…At last, one needs discuss the fate of those poles in the SU (3) limit for the purpose of pinning down the property of the desired N * (890). To study this, it is realized that [37] the SU (3) symmetry only exists in the sheet with same sign, i.e., in sheet (+, +, • • • , +) or sheet (−, −, • • • , −), and all channels should be taken in to considerations. Taking the N * (890) for example, there were only two channels being considered (i.e., N π, N η), now one has to go to four channels (N π, N η, ΛK, ΣK) in sheet (−, −, −, −).…”