Possibility of observation of supernarrow dibaryons with symmetric wave function in $\gamma d --> \pi^{\pm}+\gamma NN$ reactions

Abstract

The possibility of obsevation of supernarrow dibaryons with symmetric wave function in reactions $\gamma +d to \pi^+ +\gamma +nn$ and $\gamma +d to \pi^- +\gamma +pp$ is studied. These dibaryons satisfy the condition $(-1)^{T+S}P=+1$ (where T is the isospin, S is the internal spin and P is the dibaryon parity) and their decay into two nucleons is suppressed by the Pauly principle. In the present paper the method of a dibaryon masses reconstruction over the dibaryon decay products (\gamma nn) and (\gamma pp) is analysed. The Monte-Carlo simulation is used to choose the optimal location of the detectors, to estimate the contribution of the main background processes and to calculate the expected yields of the dibaryon production. It is shown that 100 hours of the exposition time at the microtron MAMI (Mainz) is quite enough to determine whether or not the supernarrow dibaryons with symmetric wave function exist.