Physicists close in on a rare particle-decay process - In the biggest result of its kind in more than ten years, physicists have made the most sensitive measurements yet in a decades-long hunt for a hypothetical and rare process involving the radioactive decay of atomic nuclei. If discovered, the researchers say, this process could have profound implications for how scientists understand the fundamental laws of physics and help solve some of the universe's biggest mysteries. Reference: Search for Neutrinoless Double-Beta Decay in 136Xe with EXO-200, Physical Review Letters, 2012 arXiv:1205.5608v1