*Ab Initio* many-body calculations of the ${}^{3}\mathrm{H}(d,n){}^{4}\mathrm{He}$ and ${}^{3}\mathrm{He}(d,p){}^{4}\mathrm{He}$ fusion reactions

We apply the ab initio no-core shell model combined with the resonating-group method approach to calculate the cross sections of the

^{3}H(d,n)^{4}He and^{3}He(d,p)^{4}He fusion reactions. These are important reactions for the big bang nucleosynthesis and the future of energy generation on Earth. Starting from a selected similarity-transformed chiral nucleon-nucleon interaction that accurately describes two-nucleon data, we performed many-body calculations that predict the S factor of both reactions. Virtual three-body breakup effects are obtained by including excited pseudostates of the deuteron in the calculation. Lastly, our results are in satisfactory agreement with experimental data and pave the waymore »