This new particle would have to be electrically neutral to keep charge conserved, and would carry off the majority of the kinetic energy. A nucleus is capable of being in an excited state, like electrons orbiting in an atom, and when the nucleus returns to its ground state, a photon is given off. There is no change to the nuclear structure, only an intense release of energy. These reactions are fission and fusion of nuclei. In fission, neutrons strike a heavy nucleus and cause the nucleus to split into two daughter nuclei of almost equal mass.
Fusion brings two light nuclei together to form a heavier one.
Research is underway to see if we can control the fusion reaction and obtain enough energy to make fusion a feasible source of energy. Researchers project that by the year 2010, we will be able to achieve a self-sustaining fusion reaction in reactors under development. Over the past century, mankind has made many advances in the theories about the nucleus of the atom. We still continue to learn every day about the properties and interactions of nuclei. The future is full of possibilities.