A MODEL-INDEPENDENT DESCRIPTION OF DT AND D(3)HE SYSTEMS NEAR LOW-ENERGY RESONANCES

The effective range expansion is used to obtain a model-independent de scription of dt and d(3)He systems in the vicinity of the low-energy r esonances He-5(3/2(+)) and Li-5* (3/2(+)). The Coulomb-modified nucle ar scattering lengths a(cs) and effective ranges r(cs) with angular mo mentum l = 0 as well as the astrophysical function s(E) are calculated from the modern experimental data for cross sections of the dt --> na and d(3)He --> p alpha per fusion reactions in the vicinity of the re sonances. To this end the generalization of the Smorodinsky formula fo r effective range to the case of potentials with the Coulomb barrier, as well as the phase analysis of the elastic n alpha-scattering near t he resonance He-5 (3/2(+)), are essentially used. The analytical stru cture of the scattering amplitudes in presence of absorption in the sy stem is studied. Two series of the Coulomb poles of the dt-scattering amplitude in the complex k-plane, condensing to the elastic threshold, are found.