chargeindependence
Charge independence is a concept in nuclear physics describing the approximate invariance of the strong nuclear force under changes of nucleon identity, i.e., protons and neutrons. In practical terms, it states that the interaction between any pair of nucleons—proton–proton, neutron–neutron, or proton–neutron—should be the same when electromagnetic effects are ignored. This idea is rooted in isospin symmetry, a mathematical SU(2) symmetry that treats protons and neutrons as two states of a single nucleon.
Charge independence is an approximate property. It holds well for the strong interaction but is broken by
Historically, the notion helped organize early nuclear force models and remains a benchmark for modern nuclear