The K − p → π 0 π 0 Σ 0 reaction is studied within a chiral unitary model. The distribution of π 0 Σ 0 states forming the Λ(1405) shows, in agreement with a recent experiment, a peak at 1420 MeV and a relatively narrow width of Γ = 38 MeV. We use these data in combination with those of the π − p → K 0 πΣ reaction and elements of chiral unitary theory to prove that there are two Λ(1405) states i...

www.sciencemag.org (this information is current as of October 19, 2009 ): The following resources related to this article are available online at http://www.sciencemag.org/cgi/content/full/325/5946/1405 version of this article at: including high-resolution figures, can be found in the online Updated information and services, http://www.sciencemag.org/cgi/content/full/325/5946/1405/DC1 can be fo...

Near-miss events are situations in which an action yields a negative result but is very close to being successful. They are known to influence behavior, especially in gambling scenarios. Previous neuroimaging studies have described an anomalous activity of brain reward areas following these events. The goal of the present research was to study electrophysiological correlates of near-misses in t...

The aim of the AMADEUS experiment is to investigate lowenergy antikaon interaction with nucleons and nuclei, exploiting unique lowmomentum beam kaons produced by DAΦNE collider at LNF-INFN, constrain hadronic nuclear physics models in strangeness -1 sector. As a first step data collected 2004/2005 KLOE collaboration, consisting complex K − absorptions H, 4 He, 9 Be 12 C, was analyzed, leading i...

By using techniques of unitarized chiral perturbation theory, where the Λ(1405) and Λ(1670) resonances are dynamically generated, we evaluate the magnetic moments of these resonances and their transition magnetic moment. The results obtained here differ appreciably from those obtained with existing quark models. The width for the Λ(1670) → Λ(1405)γ transition is also evaluated leading to a bran...

We study negative-parity baryon spectra in quenched anisotropic lattice QCD. The negative-parity baryons are measured as the parity partner of the ground-state baryons. In addition to the flavor octet and decuplet baryons, we pay much attention to the flavorsinglet negative-parity baryon as a three-quark state and compare it with the Λ(1405) baryon. Numerical results of the flavor octet and dec...

We report on a recent theoretical work on the structure of the Λ(1405) resonance within a chiral unitary approach, in which the resonance is dynamically generated in meson-baryon scattering. Studying the analytic structure of the scattering amplitude, we have found that there are two poles lying around energies of Λ(1405) with different widths and couplings to the meson-baryon states. We discus...