Abstract:
During the past year, the unexpected discoveries of as many as six new particles amazed those who thought that our understanding of the quark model was nearly complete. Using techniques of elementary quantum mechanics, we show why two of the discoveries were so surprising and why the others remain controversial. Understanding the hydrogen atom and the behavior of a resonance is all that is needed to address the enigmas of the narrow charmed-strange and charmonium states, and the pentaquarks.