Candidate Toroidal Electric Dipole Mode in the Spherical Nucleus ^{58}Ni

Area of Science:

• Nuclear physics
• Atomic physics
• Condensed matter physics

Background:

• Dipole toroidal modes are theoretical constructs observed across various physics domains.
• These modes were predicted in atomic nuclei over 50 years ago.
• Experimental evidence for toroidal dipole modes in nuclei has been historically elusive.

Purpose of the Study:

• To provide the first experimental evidence for toroidal dipole excitations in atomic nuclei.
• To investigate the nature of these predicted toroidal dipole modes.
• To identify suitable experimental observables for detecting toroidal dipole excitations.

Main Methods:

• Utilized high-resolution inelastic scattering experiments.
• Employed multiple probes: photons, electrons, and protons.
• Focused on the ^{58}Ni nucleus.

Main Results:

• Identified candidate toroidal dipole excitations in the ^{58}Ni nucleus.
• Demonstrated the significance of transverse electron scattering form factors.
• Provided a method to experimentally confirm the nature of toroidal dipole excitations.

Conclusions:

• The study presents the first experimental candidates for toroidal dipole excitations in nuclei.
• Transverse electron scattering form factors are crucial for verifying toroidal dipole modes.
• This work opens new avenues for studying toroidal phenomena in nuclear physics.