Recoil momentum effects in quantum processes induced by twisted photons

We consider physical processes caused by the twisted photons for a range of energy scales, including optical (eV) and nuclear (MeV). We demonstrate that in order to satisfy angular momentum conservation, absorption of a twisted photon leads to a transverse recoil of the final particle or a system of particles, leading to an increased threshold energy requirement for the reaction to proceed. Modification of the threshold energy is predicted for photoabsorption on cold trapped ions of Ca-40(+), along with emerging new transverse-motion sidebands, and for photodisintegration of deuterium.