Quarks, diquarks and pentaquarks

Pentaquarks offer exciting new insights into the subtleties of the strong interaction but fundamental properties of these exotic new particles are not known. Diquark intepretation of pentaquarks can be used to understand these particles but has many testable implications. Substantial amount of energy is needed for diquarks to overlap. To avoid this, one of the diquarks must be put into a different orbital from the other by giving it a unit of angular momentum. In this picture, the parity of the pentaquarks must be positive. This means the quantum-mechanical wavefunction remains unchanged when viewed in a mirror. Furthermore, the orbital angular momentum of the diquark can either align or anti-align with the spin of the antiquark, giving a total angular momentum of either 3 1/2 or 1/2. Finally, several related cryptoexotic pentaquarks are to be expected. A careful count gives 15 crypto-exotics, and there are already experimental candidates for some of these.