Mu2e

Mu2e, or the Muon-to-Electron Conversion Experiment, is a particle physics experiment at Fermilab in the US. The goal of the experiment is to identify physics beyond the Standard Model, namely, the conversion of muons to electrons without the emission of neutrinos, which occurs in a number of theoretical models. Project co-spokesperson Jim Miller likens this process to neutrino oscillation, but for charged leptons. Observing this process will help to narrow the range of plausible theories. The experiment will be 10,000 times more sensitive than previous muon to electron conversion experiments, and probe energy scales up to 10,000 TeV. Physicists have been searching for flavor violation since the 1940s. Flavor violation among neutrinos was proven in 1998 at the Super-Kamiokande experiment in Japan. In 1989, Russian physicists Vladimir Lobashev and Rashid Djilkibaev proposed an experiment to search for lepton flavor violation. The experiment, called MELC, operated from 1992 to 1995 at the Moscow Meson Factory at the Institute for Nuclear Research in Russia, before being shut down due to the political and economic crises of the time. In 1997, American physicist William Molzon proposed a similar experiment at Brookhaven National Laboratory. Research and development on the MECO experiment began in 2001, but funding was pulled in 2005. Mu2e is based on the MECO experiment proposed at Brookhaven, and the earlier MELC experiment at Russia's Institute for Nuclear Research. Research and development for the Mu2e experiment began in 2009, with the conceptual design complete in mid-2011. In July 2012, Mu2e received Critical Decision 1 approval (the second of five critical decision levels) from the Department of Energy, about one month after initial review. Project Manager Ron Ray asserted, "I know of no other project that has received sign-off that quickly after review." Funding of the Mu2e experiment was recommended by the Department of Energy's Particle Physics Project Prioritization Panel, in its 2014 report.