Lambda(1405) in a baryon-meson scattering with a bound state embedded in the continuum

Abstract

We investigate Lambda(1405) as a resonance in a coupled channel baryon-meson scattering with a `bound state embedded in the continuum'(BSEC). This BSEC is introduced by hand, as a state not originated from simple baryon-meson systems. We assume it comes from the three-quark state. There appears a resonance in the Sigma pi scattering below the N Kbar threshold when the N Kbar channel is taken to be strongly attractive. It occurs without introducing a BSEC, just like the chiral unitary approach. When a BSEC is introduced, a resonance also appears with a weaker baryon-meson interaction. The corresponding peak also has a large width, and the N Kbar scattering length is reproduced well. The interaction whose channel dependence is the same as the one originated from the color-magnetic interaction, where no N Kbar attraction exists, also gives a broad peak like Lambda(1405) with help of a BSEC. It is found that the BSEC coupling which does not vanish at the zero momentum transfer give a larger width. In order to reproduce the observed N Kbar scattering length, introducing a BSEC seems preferable. In our calculation, a model gives an appropriate value when the BSEC contribution to the resonance is roughly half of that of the N Kbar in size.

19 pages, 9 figures

References in corpus (9)

• The Cosmological Parameters 2006
• Big-Bang nucleosynthesis (Particle Data Group mini-review)
• Strange dibaryon resonance in the anti-KNN--piYN system
• Evidence for the two pole structure of the Lambda(1405) resonance
• Origin of resonances in the chiral unitary approach
• A critical view on the deeply bound K^- pp system
• $\bar{K}$ nuclear bound states in a dynamical model
• Lambda(1405) as a Resonance in the Baryon-Meson Scattering Coupled to the q^3 State in a Quark Model
• Structure of Lambda(1405) and chiral dynamics

Cited by in corpus (3)

• Comprehensive application of a coupled-channel complex scaling method to the KbarN-piY system
• Double-pole nature of $\Lambda (1405)$ studied with coupled-channel complex scaling method using complex-range Gaussian basis
• Charmonium and meson-molecule hybrid tetraquarks - Vector meson width and the isospin breaking in the X(3872) decay