The nature of the Lambda(1405)

Abstract

We present here some results supporting the nature of the $\Lambda (1405)$ resonance as dynamically generated from the meson baryon interaction in coupled channels and resulting from the superposition of two close-by poles. We find support for this picture in the $K^{-}p\to {\pi }^0{\pi }^0{\Sigma }^0$ reaction, which shows a different shape than the one obtained from the ${\pi }^{-}p\to K^0\pi \Sigma$ reaction. We also call the attention to the $K^{-}p\to \gamma \pi \Sigma$ with $\pi \Sigma$ in the $\Lambda (1405)$ region, which shows a narrow peak in the calculations around 1420 MeV. We also report on recent calculations of the radiative decay of the two $\Lambda (1405)$ states and on reactions to obtain information on these decay modes. Finally, we present results for the $pp\to p{K}^{+}\Lambda (1405)$ reaction recently measured at ANKE/COSY and compare them with theoretical results.

Talk given at the NSTAR2007 Workshop, Bonn September 2007

References in corpus (10)

• K^- p scattering length from scattering experiments
• Evidence for the two pole structure of the Lambda(1405) resonance
• Chiral dynamics of kaon-nucleon interactions, revisited
• On the Strangeness -1 S-wave Meson-Baryon Scattering
• Lineshape of the Lambda(1405) Hyperon Measured Through its Sigma0 pion0 Decay
• Surprises in threshold antikaon-nucleon physics
• SU(6) Extension of the Weinberg-Tomozawa Meson-Baryon Lagrangian
• Helicity amplitudes and electromagnetic decays of hyperon resonances
• The radiative decay of the $\Lambda (1405)$ and its two-pole structure
• Radiative Decays of Decuplet Baryons, $\Lambda (1405)$ and $\Lambda (1520)$ Hyperons