# How can there be nuclear spin-orbit interactions with only neutral and positively charged particles in the nucleus?

At the atomic level, spin-orbit interaction is motivated by the magnetic field experienced by the negatively charged electron orbiting the positively charged nucleus.

However, at the nuclear level, there are only neutral (neutrons) and positively charged nucleons (protons). How can there still be a spin-orbit interaction then?

• According to your model the neutron should posses no magnetic moment. However, its mag. moment is unequal to zero. The concept of spin is independent of the electric charge, and so is the spin orbit coupling. – Semoi Mar 15 '20 at 17:00

The motion of the positively-charged protons within the nucleus creates a magnetic field. Protons and neutrons both have magnetic moments, so their interaction energy with this field is $$-\vec{\mu}\cdot\vec{B}$$.