相关论文: New insights into the pole parameters of the $\Lam…
The reaction gamma + p -> K+ + Sigma + pi was used to determine the invariant mass distributions or "line shapes" of the Sigma+ pi-, Sigma- pi+ and Sigma0 pi0 final states, from threshold at 1328 MeV/c^2 through the mass range of the…
The $\Lambda(1520)$ resonance has been recently studied in a unitarized coupled channel formalism with $\pi\Sigma(1385)$, $K\Xi(1530)$, $\bar{K}N$ and $\pi\Sigma$ as constituents blocks. We provide a theoretical study of the predictions of…
We examine the internal structure of the $\Lambda(1670)$ through an analysis of lattice QCD simulations and experimental data within Hamiltonian effective field theory. Two scenarios are presented. The first describes the $\Lambda(1670)$ as…
A production representation of partial-wave $S$ matrix is utilized to construct low-energy elastic pion-nucleon scattering amplitudes from cuts and poles on complex Riemann sheets. Among them, the contribution of left-hand cuts is estimated…
A local coupled-channels Kbar N-pi Sigma-pi Lambda potential is constructed, equivalently reproducing the scattering amplitude in chiral SU(3) dynamics. By analyzing the wave function of the Lambda(1405), we show the Kbar N dominance of the…
Properties of scalar--isoscalar mesons in a mass range from pi-pi threshold up to 1800 MeV are analysed using an unitary model with separable interactions in three decay channels: pi-pi, K-anti K and an effective 2pi-2pi. Different…
The $S$-wave $\Lambda K$ and $\Sigma K$ states with isospin $I=1/2$ are dynamically investigated within the framework of the chiral SU(3) quark model by solving a resonating group method (RGM) equation. The model parameters are taken from…
The unquenched quark models predict the new particle $\Sigma^*$ with spin parity $J^P=1/2^-$ and its mass is around the well established $\Sigma^*(1385)$ with $J^P=3/2^+$. Here by using the effective Lagrangian approach we study \kp\…
Recent studies of the $\Lambda(1520)$ resonance within chiral unitary theory with coupled channels find the resonance as a dynamically generated state from the interaction of the decuplet of baryons and the octet of mesons, essentially a…
We present a lattice-QCD determination of the elastic isospin-$1/2$ $S$-wave and $P$-wave $K\pi$ scattering amplitudes as a function of the center-of-mass energy using L\"uscher's method. We perform global fits of $K$-matrix…
We have performed a thorough study of the meson-meson S-waves with isospin (I) 0 and 1/2, up to sqrt(s) ~ 2 GeV. This is the first study that includes 13 channels that have their threshold below that energy. All the resonances below 2 GeV,…
Masses, widths, and branching ratios of hadronic resonances are quantified by their pole positions and residues with respect to transition amplitudes on the Riemann sheets of the complex energy-plane. In this study we discuss the analytic…
We present the results of a coupled-channel model for $\bar{K}N$ scattering in the resonance region. The model fulfills unitarity, has the correct analytical properties for the amplitudes and the partial waves have the right threshold…
The analysis of the poles of the $\pi\pi$ scattering amplitude is shown to favour a dynamical origin of the sigma meson: it is created by a strongly attractive $\pi\pi$ interaction in the $J^{PC}=0^{++}I=0$ channel. In the limit…
In a combined analysis of the experimental data on the coupled processes $\pi\pi\to\pi\pi,K\bar{K}$ in the channel with $I^GJ^{PC}=0^+0^{++}$, the various scenarios of these reactions (with different numbers of resonances) are considered.…
By separating data points close to a resonance into intervals, and fitting all possible intervals to a simple pole with constant coherently added background, we obtained a substantial number of convergent fits. After a carefully chosen set…
We study the $\Lambda(1520)$ resonance in a coupled channel approach involving the $\pi\Sigma(1385)$, $K\Xi(1530)$, $\bar{K}N$ and $\pi\Sigma$ channels. Implementing unitarity in coupled channels, we make an analysis of the relative…
Studies on the IJ=00 $\pi\pi$ and $K\bar K$ coupled--channel system are made using newly derived dispersion relations between the phase shifts and poles and cuts. It is found that the $\sigma$ resonance must be introduced to explain the…
Recent experimental results for the reaction \gamma + p \to K^+ + \Sigma + \pi\ from CLAS at Jefferson Lab are discussed. It was found that the mass distributions or "line shapes" of the three charge combinations \Sigma^+ \pi^-, \Sigma^0…
We revisit the information on the two lightest $a_0$ resonances and $S$-wave $\pi\eta$ scattering that can be extracted from photon-photon scattering experiments. For this purpose we construct a model for the $S$-wave photon-photon…