We investigate the interaction of high-energy vortex photons with atomic nuclei. By performing a multipole expansion of the optical-vortex field, we show that the selection rules arise from the intrinsic symmetries of the vortex field. This rule governs on-axis nuclear transitions and breaks down off-axis, where extrinsic orbital angular momentum (OAM) enables otherwise forbidden excitations. By incorporating the finite size of both the photon wave packet and the nucleus through a spatiotemporal luminosity function, we show that although the on-axis absorption cross section can be locally enhanced by several orders of magnitude, the total excitation probability remains low due to vanishing field intensity at the vortex core. As a result, most nuclear transitions show negligible selectivity in probability. In contrast, nuclear hyperfine transitions can be selectively driven by vortex photons, particularly in the nonparaxial regime, where photon OAM enables sublevel-specific excitation and external-field-sensitive control of nuclear states.

Close

PrevNext

View figure in article

• Electromagnetic transitions
• Photonuclear reactions
• Structured light
• Angular momentum