We present a phenomenological study of the ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(d,γ${)\mathrm{}}^4$He reaction that allows for the D-state component of the colliding deuterons. The low-energy cross section is determined by an interference between E2 transitions from an initial ${}_{}{}^5{}_{}{}^{}\mathrm{S}_2^{}{}_{}{}^{}$ scattering state to either the D- or S-state components of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$, the latter via the internal quadrupole moment of the deuteron. From a fit to the data, we determine the asymptotic D/S ratio of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ to be ρ∼-0.40.

• Received 17 April 1987

DOI:https://doi.org/10.1103/PhysRevC.36.875