majid313mirzae said:All nuclei with A > 210 are alpha emitters, yet very few emit protons spontaneously.
Yet both decays lower the Coulomb energy of the nucleus. Why is
proton decay not more common?
Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle, which consists of two protons and two neutrons. This process occurs in heavy and unstable nuclei in order to reach a more stable state.
Proton decay is a hypothetical process in which a proton, one of the building blocks of an atomic nucleus, spontaneously decays into lighter particles. This process has not been observed in experiments, but is predicted by certain theories of physics beyond the standard model.
The rates of alpha and proton decay differ because they involve different fundamental forces. Alpha decay is governed by the strong nuclear force, which is a short-range force that binds protons and neutrons together in the nucleus. Proton decay, on the other hand, is thought to be governed by the much weaker grand unified force, which operates on a larger scale.
The rate of alpha decay is determined by the nuclear binding energy of the parent nucleus and the mass of the daughter nucleus. This rate is also affected by the presence of any energy barriers that the alpha particle must overcome in order to escape the nucleus. The higher the binding energy and lower the energy barriers, the slower the rate of alpha decay will be.
The unequal rates of alpha and proton decay can be explained by the differences in the fundamental forces involved in each process. The strong nuclear force that governs alpha decay is much stronger than the grand unified force that is thought to govern proton decay. Therefore, the rate of alpha decay is much slower than that of proton decay.