Angular Momentum Dynamics of Vortex Particles in Accelerators

While conventional experiments typically employ plane-wave states of particles with definite momenta, vortex states represent cylindrical waves carrying an orbital angular momentum (OAM) projection along the propagation direction. This projection can be arbitrarily large, granting charged particles magnetic moments orders of magnitude greater than those of plane-wave states. Consequently, vortex beams could complement or replace spin-polarized beams in high-energy collisions, accessing observables beyond the reach of conventional experiments. We investigate the radiative and nonradiative OAM dynamics for relativistic vortex particles in accelerators. Our results show that the timescale for OAM loss via photon emission significantly exceeds typical acceleration times. Nonradiative OAM dynamics is governed by precession at a frequency distinct from that of spin. Similar to spin tunes, this induces resonances that can disrupt OAM at much lower energies than for spin-polarized beams. Thus, we propose using linacs for acceleration of the vortex beams, while Siberian snakes can be adapted for OAM manipulations.