Cold Neutron Capture on the Deuteron in Pionless Effective Field Theory*

Cold neutron capture on the deuteron to create the triton and emit a photon ($nd\to \gamma t$) at low energies is an important process for big bang nucleosynthesis; the time reversed process is relevant for experiments at the Triangle Universities Nuclear Laboratory (TUNL)/High Intensity Gamma Source (HIGS). For momentum transfer well below the pion mass, pionless effective field theory (EFT) is valid and provides a systematic expansion for the calculation of amplitudes. In this work, we calculate the cross section of $nd\to \gamma t$ to next-to-leading order in pionless EFT strictly perturbatively. We will discuss the context of this calculation and its potential impact on polarization-induced asymmetries.