The paper is devoted to the \bar{K}NNNK‾NNN
system, consisting of an antikaon and three nucleons. Four-body
Faddeev-type AGS equations are being solved in order to find possible
quasi-bound state in the system.
The SRC/BM@N experiment was carried out in the 55th run of the Nuclotron using a liquid hydrogen target and a carbon beam with a kinetic energy of about 3.1 GeV/n. We propose to analyze the experimental data to search for a quasi-bound state of η-meson and nucleons in the reaction 12C+p → η(A-1)+X → π+p+(A-2). To achieve this goal, it is necessary to identify the residual nucleus (A-2) and the proton-pion pair formed from η-nuclei decay.
Necessary conditions of quasi-bound state formation of η-meson with isotopes3He,4He have been found within the framework of optical potential model. These conditions have been compared with the findings about helium nucleus densities and with the available information about ηN-scattering length. Thus, we have concluded that within the framework of discussed model η−3He quasi-bound state formation is not possible, but η−4He quasi-bound state formation is possible with great probability.