Related papers: $^3_\eta He$ nucleus modeling in the frame optical…
The necessary conditions of quasi-bound state formation of $\eta$-meson with isotopes $^{3}$He, $^{4}$He have been found within the framework of optical potential model. These conditions have been compared with the findings about helium…
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…
The existence of etamesic nuclei has been speculated for a long time without firm experimental evidence. Much of the effort has taken place in final state interactions on production. One crucial factor in seeing a quasibound state is its…
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 possibility for the existence of unstable bound states of the S11 nucleon resonance N$^*$(1535) and nuclei is investigated. These quasibound states are speculated to be closely related to the existence of the quasibound states of the…
Starting from a recent model of the eta'N interaction, we evaluate the eta'-nucleus optical potential, including the contribution of lowest order in density, t rho/2m_eta', together with the second order terms accounting for eta' absorption…
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…
In a recent paper by the TAPS collaboration \cite{exp} a first measurement of a bound system of an $\eta$ meson and a ${^3}$He nucleus was reported. In this comment we critically reexamine the interpretation of the data and show that the…
The optical potential for the $\eta$-meson is calculated. This is based on a new determination of a large $\eta$-N scattering length and recent experiments of $\eta$ production in two nucleon collisions. These determine the $\eta$ - nuclear…
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…
The optical potential approach for low-energy scattering of $\eta$-mesons on three-body nuclei is compared to an exact treatment of the $\eta 3N$ system using four-body scattering theory with separable interactions in s-waves only. The…
We investigate the relation between the \eta ^3He binding energy and width and the (complex) \eta ^3He scattering length. Following our systematic analysis of the eta 3He scattering length we set limits on the \eta ^3He binding. If bound…
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 analyze the data on cross sections and asymmetries for the $pd (dp) \to \eta ^3{\rm He}$ reaction close to threshold and look for bound states of the $\eta ^3 {\rm He}$ system. Rather than parameterizing the scattering matrix, as is…
The $\eta$ meson can be bound to atomic nuclei. Experimental search is discussed in the form of final state interaction for the reactions $dp\to{^3\text{He}}\eta$ and $dd\to{^4\text{He}}\eta$. For the latter case tensor polarized deuterons…
It is argued that the strong energy dependence of the $p\, d \rightarrow \,^{3\!}H\!e\, \eta$ cross section near threshold is due to a final state interaction between the $\eta$ meson and the $^3$He nucleus. The large scattering length that…
In this contribution we report on theoretical studies of $\eta$ nuclear quasi-bound states in few- and many-body systems performed recently by the Jerusalem-Prague Collaboration [1-5]. Underlying energy-dependent $\eta N$ interactions are…
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…
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…
The search for a quasi bound $\eta$ meson in atomic nuclei is reviewed. This tentative state is studied theoretically as well as experimentally. The theory starts from elastic $\eta$ nucleon scattering which is derived from production data…