Frank Wilczek in Inference:
Quantum mechanics is nearly one hundred years old, and yet the challenge it presents to the imagination is so great that scientists are still coming to terms with some of its most basic implications. Here I will describe some theoretical insights and recent experimental results that are leading physicists to revise and expand their ideas about what quantum-mechanical particles are and how they behave. These new ideas are centered around a topic traditionally known as quantum statistics. The name is misleading: the basic physical phenomena do not involve statistics in the usual sense. A better title might have been the quantum mechanics of identity, but the new developments make that name obsolete too. A more accurate description would be the quantum mechanics of world-line topology. Since that is quite a mouthful, most researchers now simply refer to anyon physics.