New Constraints on Radiative Decay of Long-Lived Particles in Big Bang Nucleosynthesis with New ${}^4$He Photodisintegration Data

Motohiko Kusakabe, Toshitaka Kajino, Takashi Yoshida +3

A recent measurement of ${}^4$He photodisintegration reactions, ${}^4$He($\gamma$,$p$)${}^3$H and ${}^4$He($\gamma$,$n$)${}^3$He with laser-Compton photons shows smaller cross sections than those esti…