The IBD reaction can only be initiated when the antineutrino possesses at least 1.806 MeV of kinetic energy (called the threshold energy). This threshold energy is due to a difference in mass between the products ( and ) and the reactants ( and ) and also slightly due to a relativistic mass effect on the antineutrino.
The IBD reaction can only be triggered when the antineutrino has at least 1.806 MeV of kinetic energy (known as the threshold energy). This threshold is caused by a difference in mass between the products and reactants, along with a minor relativistic effect on the antineutrino.