Relations between spin observables of the reactions $dd\to npd$ and $pd\to pd$ in impulse approximation

It is shown that the vector and tensor analyzing powers $A_y$, $A_{yy}$ and also double spin correlation coefficients $C_{y,y}$, $C_{yy,y}$ of the reaction $dd\to n+p+d$ in impulse approximation are linearly connected to corresponding observables of the $pd$- elastic scattering. Obtained relations are necessary for motivation of the polarization experiments for the first phase of the SPD NICA project and for analysis of expected data.