相关论文: Threshold scattering of the eta-meson off light nu…
The position and movement of poles of the amplitude for elastic eta-meson scattering off the light nuclei d, t, ^3He, and ^4He are studied. It is found that, within the existing uncertainties for the elementary eta-N interaction, all these…
The \eta-meson collision with light nuclei, ^2H, ^3H, ^3He, and ^4He, is considered on the basis of a microscopic approach which utilises Faddeev type and Lippmann-Schwinger equations. The nuclear hamiltonian is approximated by the finite…
A microscopic treatment of eta-nucleus system is presented. Using this, the poles of the amplitude describing elastic scattering of eta-meson off the light nuclei ^2H, ^3H, ^3He, and ^4He have been located in the second quadrant of the…
We demonstrate that the binding energies and widths of eta-mesic nuclei depend strongly on subthreshold eta-N interaction. This strong dependence is made evident from comparing three different eta-nucleus optical potentials: (1) a…
A microscopic treatment of $\eta$--nucleus scattering is presented. When applying the underlying exact integral equations, the excitation of the target are neglected, and an input $\eta N$ amplitude is chosen which reproduces the…
The scattering length for the eta-meson collision with deuteron is calculated on the basis of rigorous few-body equations (AGS) for various eta-N input. The results obtained strongly support the existence of a resonance or quasi-bound state…
With the eta-nucleon (eta N) interaction Lagrangian deduced from chiral perturbation theory, we study the possible eta-mesic nuclei in the framework of relativistic mean-field theory. The eta single-particle energies are sensitive to the…
The possible existence of $\eta$-mesic nuclei poses an interesting and still open issue of research. Since the occurence of such $\eta$-nucleus bound states is reflected in the corresponding $\eta$-nucleus scattering length, we critically…
Using multiple scattering theory the scattering lengths of $\eta$ mesons on helium nuclei are calculated and checked against final state $\eta$ interactions from the $pd \rightarrow \eta ^3$He and $dd \rightarrow \eta ^4$He reactions. The…
The possibility of etamesic nuclei remains an open problem in nuclear physics until now. Various calculations give contradictory predictions even for the lightest real nucleus $^3$He. In this paper we present the connection of the binding…
The coupled eta-N, pi-N, gamma-N, 2pi-N system is described by a K-matrix method. The parameters in this model are adjusted to get an optimal fit to pi-N-->pi-N, pi-N-->eta-N, gamma-N-->pi-N and gamma-N-->eta-N data in an energy range of…
The resonance and bound--state poles of the amplitude describing elastic scattering of $\eta$-meson off the light nuclei $^2H$,\,$^3H$,\, $^3He$, and $^4He$ are calculated in the framework of a microscopic approach based on few--body…
p-3H and n-3He scattering in the energy range above the n-3He but below the d-d thresholds is studied by solving the 4-nucleon problem with a realistic nucleon-nucleon interaction. Three different methods -- Alt, Grassberger and Sandhas,…
The $\eta$-nucleon ($\eta$N) interactions are deduced from the heavy baryon chiral perturbation theory up to the next-to-leading-order terms. Combining the relativistic mean-field theory for nucleon system, we have studied the in-medium…
A study of the $\eta$-3N interaction in the energy region near the $\eta$-^3H elastic scattering threshold is presented. The calculational scheme is based on the four-body scattering formalism. A manageable form of the integral equations is…
Unstable states of the eta meson and the 3He nucleus predicted using the time delay method were found to be in agreement with a recent claim of eta-mesic 3He states made by the TAPS collaboration. Here, we extend this method to a…
Using the new set of dd --> eta alpha near threshold experimental data, the estimate of the importance of the nucleon-nucleon correlations for the eta alpha S-wave scattering length in the multiple scattering theory is obtained using the…
The coupled eta N, pi N system is described by a K-matrix method. The parameters in this model are adjusted to get an optimal fit to pi N -> pi N, pi N -> eta N and gamma N -> eta N data in an energy range of about 100MeV each side of the…
We present results on the scattering lengths of ^4He--^4He_2 and ^3He--^4He_2 collisions. We also study the consequence of varying the coupling constant of the atom-atom interaction.
With the aim at quantitatively investigating the longstanding problem concerning the effect of short range nucleon-nucleon correlations on scattering processes at high energies, the total neutron-nucleus cross section is calculated within a…