Photodisintegration of deuterium and big bang nucleosynthesis

Photodisintegration cross sections were measured for deuterium with Laser-Compton scattering $\ensuremath{\gamma}$ beams at seven energies near threshold. Combined with the preceding data, ${R(E)=N}_{a}\ensuremath{\sigma}v$ for the $p(n,\ensuremath{\gamma})\mathrm{D}$ reaction is for the first time evaluated based on experimental data with 6% uncertainty in the energy region relevant to the big bang nucleosynthesis (BBN). The result confirms the theoretical evaluation on which the BBN in the precision era relies.