The first particles that show an interesting symmetry are actually the nucleon and the proton. This symmetry is reinforced by the discovery that the interactions between nucleon (\(p\) and \(n\)) is i...The first particles that show an interesting symmetry are actually the nucleon and the proton. This symmetry is reinforced by the discovery that the interactions between nucleon (\(p\) and \(n\)) is independent of charge, they only depend on the nucleon character of these particles – the strong interactions see only one nucleon and one pion. The symmetry that was proposed (by Wigner) is an internal symmetry like spin symmetry called isotopic spin or isospin.
Nuclei are quantum systems, and as such must be described by a quantum Hamiltonian. Fortunately nuclear energies are much smaller than masses, so that a description in terms of non-relativistic quantu...Nuclei are quantum systems, and as such must be described by a quantum Hamiltonian. Fortunately nuclear energies are much smaller than masses, so that a description in terms of non-relativistic quantum mechanics is possible. Such a description is not totally trivial since we have to deal with quantum systems containing many particles. Rather then solving such complicated systems, we often resort to models.
