The peculiar wobble of a subatomic particle called a muon in a US laboratory experiment is making scientists increasingly suspect they are missing something in their understanding of physics - perhaps some unknown particle or force. Researchers on Thursday announced new findings about the muon (pronounced MEW-on), a magnetic and negatively charged particle similar to its cousin the electron but 200 times more massive, in their experiment at the US Energy Department's Fermi National Accelerator Laboratory in Batavia, Illinois.