Phase Transitions and the Unparticles

Another Odd Thing About Unparticle PhysicsHoward Georgi

The peculiar propagator of scale invariant unparticles has phases that produce unusual patterns of interference with standard model processes. We illustrate some of these effects in e+e− → µ+µ−.

To be a bit more precise, every space that feels "real" has associated with it a sense of distance between any two points. On a line segment like the Koch coastline, we arbitrarily chose the length of one side of the first iterate as a unit length. On the Euclidean coordinate plane the distance between any two points is given by the Pythagorean theorem

Fractals have a special property that underpins the odd features of unparticles. They are patterns that are "scale invariant". In the case of Britain, the ins and outs of the coastline contain smaller jagged features that in turn contain smaller ins and outs and so on. This characteristic means that these unparticles don't change appearance when viewed at different scales- which is very different from objects we're familiar with.