Grant: Subatomic Physics Envelope - Project

One of the main challenges in subatomic physics at this time is to find the limits of validity of our model of fundamental particle interactions. This model, known as the Standard Model of particle physics, has been extremely successful at predicting experimental observations. Nevertheless, we believe it is only an approximation to a more general theory or model, much as Newton's gravity was an approximation to Einstein's theory. A way to meet this challenge is with more and more precise experiments. One recent and very precise experiment was the measurement of the magnetic strength of the muon, a fundamental subatomic particle normally found only in cosmic rays or at particle accelerators. It seems that this magnetic strength is not quite what the Standard Model would predict, but is about two and a half parts per billion larger. This difference is small but important. If it is real, it may help to point the way to a theory beyond the Standard Model. In order to find out if it is real, the measurement must be repeated, if possible in a different way, to see if it is really telling us what a replacement for the Standard Model might look like. The experiments are extremely challenging, but the rewards are great in terms of our understanding of particle physics.