Related papers: What We Know About the Lambda(1405)
We consider meson-baryon interactions in S-wave with strangeness -1. This is a non-perturbative sector populated by plenty of resonances interacting in several two-body coupled channels.We study this sector combining a large set of…
A combined analysis of the reactions $\pi^-p\rightarrow K^0\Lambda$ and $\eta n$ is carried out with a chiral quark model. The data in the center-of-mass (c.m.) energy range from threshold up to $W\simeq 1.8$ GeV are reasonably described.…
The Cabibbo-favored decay $\Lambda_c^+ \to n \bar{K}^0\pi^+$ offers a unique window to explore unresolved puzzles in the low-energy baryon spectroscopy and the isospin dynamics of the $\bar{K}N$ system. Recent experimental results present…
We discuss properties of baryon resonances belonging to the Nucleon, Delta, Sigma, Lambda, Xi and Omega families in a collective string-like model for the nucleon, in which the radial excitations are interpreted as rotations and vibrations…
We discuss the mechanisms that lead to $\Lambda(1405)$ production in the $\pi^-p\to K^0\pi\Sigma$ reaction. The problem has gained renewed interest after different works converge to the conclusion that there are two resonances around the…
A previously introduced relativistic energy density functional, successfully applied to ordinary nuclei, is extended to hypernuclei. The density-dependent mean field and the spin-orbit potential are consistently calculated for a $\Lambda$…
Inspired by the latest BESIII measurement of the $\Lambda(1520)\to\gamma\Sigma^0$ radiative decay, we systematically study the decays $\Lambda(1520)\to\gamma\Lambda(\Sigma^0)$ within the chiral unitary approach, where the $\Lambda(1520)$ is…
We explore some of the rich structure of the polarization observables recently developed for processes like $\gamma N\to\pi\pi N$ and $\gamma N\to K \bar{K} N$ in the framework of a specific model for the latter process. Emphasis is placed…
General interest in a precise determination of the threshold pi-pi amplitudes has recently increased markedly due to a controversy regarding the size of <0|qbar q|0>, the scalar quark condensate. This paper examines the current experimental…
The strong and electromagnetic properties of the Lambda(1405) hyperon are studied in the framework of the bound state soliton model. We explicitly evaluate the strong coupling constant g(Lambda^*-N-K), the Lambda^* magnetic moment, mean…
Chiral perturbation theory and its unitarized versions have played an important role in our understanding of the low-energy strong interaction. Yet, so far, such studies typically deal exclusively with perturbative or nonperturbative…
We review two manifestations of chiral symmetry breaking in the pion sector. First, we examine the $\pi\pi$ scattering amplitude at threshold, which is completely determined by the chiral symmetry breaking part of the strong interaction,…
Recent studies within the framework of chiral unitary theory produce the $\Lambda (1520)$ resonance, among several others, as a dynamically generated resonance from the interaction of the baryon decuplet and the meson octet. The $\Lambda…
pi pi scattering at low energy is sensitive to the structure of the QCD vacuum. I review the calculations of the pi pi scattering lengths and phases, and group them in three cathegories: 1. those based on very general theoretical…
We present a theoretical analysis of the process $\Lambda_c^+ \to p\bar{K}^0 \pi^0$ within the chiral unitary approach, with particular emphasis on the dynamically generated $N(1535)$ resonance. In addition to $N(1535)$, our model…
Based on the recent phenomenological analysis done by M. Mojzis, Eur. Phys. Jour. {\bf C2} (1998) 182, of $\pi N $ scattering within the framework of Heavy Baryon Chiral Perturbation Theory we predict, after a suitable unitarization of the…
Coupled channels model of meson-baryon interactions based on the effective chiral Lagrangian is extended to account explicitly for the $\Sigma(1385)$ resonance that dominates the $P$-wave $\bar{K}N$ and $\pi\Sigma$ interactions at energies…
A phenomenological model for the Kbar N --> K Xi reaction is suggested. The model includes s and u channel exchanges by Lambda, Sigma, Sigma(1385), and Lambda(1520) and s channel exchanges by above-threshold hyperonic resonances. Explicit…
We develop a generalized version of heavy-baryon chiral perturbation theory to describe pion-nucleon scattering in a kinematic domain that extends continuously from threshold to the delta-isobar peak. The $P$-wave phase shifts are used to…
We work out predictions of the Linear Sigma Model for the $\gamma \gamma \to\pi^0 \pi^0$ cross section. We consider the sigma width, which is introduced in a consistent way with chiral Ward identities. The results of Chiral Perturbation…