相关论文: Light Baryon Resonances: Restrictions and Perspect…
We discuss that some light baryon resonances exhibit properties which cannot be described when attributing a three-valence quark structure to them. Besides pointing out the hadron resonances which clearly require description beyond the…
Recent neutron star observations suggest that the masses and radii of neutron stars may be smaller than previously considered, which would disfavor a purely nucleonic equation of state. In our model, we use a the flavor SU(3) sigma model…
Regular sequences of narrow peaks have been observed in the missing mass spectra in the reactions pp --> p pi^+ X and pd --> ppX_1 below pion-production threshold. They are interpreted in the literature as manifestations of supernarrow…
The spectroscopy of light, strange baryons have been an important aspect with still unknown resonances and intrinsic baryonic properties. The present document is focused on the $\Delta$ baryons unlike earlier work, here all the four isospin…
A version of the bound state soliton model which allows both $\eta$ and $K$ bound states is used to study low partial wave octet baryon resonances. It is found that negative parity $S-$wave resonances are well described within this…
The main features of nuclear reactions with participation of baryon resonances ($\Delta$(1232), S(1535) and $\Lambda$(1405)), which are interpreted as a manifestation of the bound states of nucleus and corresponding meson are discussed.
Recently several proposals were put forward to determine the parity of narrow baryonic resonances, in particular the $\Theta^+$. In these proceedings we will briefly comment on the general problems in this task and then discuss in detail…
The recent Review of Particle Physics [1] includes a new narrow N*(1685) resonance. Its properties, the narrow width and the strong photoexcitation on the neutron, are unusual. The paper reviews experimental data which have led to the…
We revise the role played by symmetry in the study of the low-lying baryon spectrum and comment on the difficulties when trying to generalize the symmetry pattern to higher energy states. We show that for the $(N,\Delta)$ part such a…
We review the status as regards the existence of three- and four-body bound states made of neutrons and $\Lambda$ hyperons. For interesting cases, the coupling to neutral baryonic systems made of charged particles of different strangeness…
We consider lepton-neutron (and lepton-antineutron) bound states and resonances which appear due to spin-spin, spin-orbital interactions,neutron polarization by muon. Our analis is also true for any system which include one charge and one…
We extend the 1/N_c meson-baryon scattering formalism to pi N to multi-pi N case. We first show that the leading-order large N_c processes proceed through resonant intermediate states (e.g., rho N or pi Delta). We find that the pole…
Light-baryon resonances with u,d, and s quarks only can be classified using the non-relativistic quark model. When we assign to baryon resonances with total angular momenta J intrinsic orbital angular momenta L and spin S we make the…
We extend the 1/N_c expansion meson-baryon scattering formalism to cases in which the final state contains more than two particles. We first show that the leading-order large N_c processes proceed through resonant intermediate states (e.g.,…
By applying a relativistic mean-field description of neutron star matter with density dependent couplings, we analyse the properties of two different matter compositions: nucleonic matter with delta baryons and nucleonic matter with…
We analyze the currently available observations of X-ray binaries in a consistent way, to re-determine the masses of the neutron stars in these systems. In particular, our attention is focussed on a realistic and consistent assessment of…
We present results from Brueckner-Hartree-Fock calculatons for beta stable neutron star matter with nucleonic and hyperonic degress degrees of freedom, employing the most recent parametrizations of the baryon-baryon interaction of the…
We present results from many-body calculations for \beta-stable neutron star matter with nucleonic and hyperonic degrees of freedom, employing the most recent parametrizations of the baryon-baryon interaction of the Nijmegen group. It is…
We review recent progress in our understanding of the nucleon excitation spectrum. Thanks to dedicated efforts at facilities such as ELSA, MAMI and Jefferson Lab, several new nucleon resonances have been discovered, and evidence for…
It is seen by a coupled-channel calculation that in the two-baryon N-Delta or Delta-Delta system the width of the state is greatly diminished due to the relative kinetic energy of the two baryons, since the internal energy of the particles,…