Novel approach to infer the H2(p,γ)He3 angular distribution: Experimental results and comparison with theoretical calculations

The $\text{D}(p,\gamma ){}^3\mathrm{He}$ reaction, where ‘D’ denotes ‘${}^2\mathrm{H}$’, is of primary importance in cosmology and nuclear physics since it offers a unique opportunity to test predictions based on the description of nuclear interactions. We present a novel approach to extract the angular distribution of the photons emitted by the $\text{D}(p,\gamma ){}^3\mathrm{He}$ reaction inferred from the shape of the experimental $\gamma$ spectra. The measurement was performed in the Gran Sasso Laboratories by the LUNA collaboration. By using a HPGe detector faced to an extended deuterium gas target, it was possible to derive the angular distribution in the 30–280 keV kinetic energy range and to compare the results with recent ab initio predictions.