He4D-state effects in theH2(d,γ)4He reaction at low energies

The ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(d, γ${)}^4$He cross section was measured for deuteron laboratory energies between 0.7 and 4.5 MeV. Angular distributions were obtained at laboratory energies of $E_{\mathrm{d}=1.38\mathrm{}}$, 2.05, 9.6, and 15.0 MeV. These data indicate that the D state of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$, which can be populated via S-wave capture in this reaction, has a large effect on the energy and angle dependence of this low energy capture cross section. The data are shown to imply an asymptotic D-to-S state ratio ρ=-0.2±0.05. The implication of this observation for the absolute cross section below 1.0 MeV is discussed.