Isospin invariance and the spin structure of the amplitude for the process ³H+³He→d²H+⁴He

We analyzed the general form of all polarization effects in the ³H+³He→d²H+⁴He reaction. For this aim, we parametrized the spin structure of the full amplitude in terms of the transverse amplitudes which describe the different transitions between initial and final states, which in turn are differed by projections of nuclei spins along the normal to the reaction plane. The isospin invariance of the strong interaction generates definite symmetry properties of the transverse amplitudes relative to the change cosθ→-cosθ, where θ is the deuteron production angle in the c.m.s. We found all symmetry relations for the polarization observables in the ³H+³He→d²H+⁴He reaction, which are the generalized form of the well-known Barshay-Temmer theorem. We consider the one-, two-, and triple-spin correlations in ³H+³He→d²H+⁴He. For analysis of the triple-spin correlations, we focus on the structure functions formalism and show that a set of 41 structure functions describes all such correlations. Isospin invariance simplifies the spin structure of the full amplitude at θ=90°; therefore, we calculated all polarization observables for this special kinematics. © 1996 The American Physical Society.