page_title: Muon g-2
section_title: Design
hierarchical_section_title: Muon g-2 / Design
caption_attribution_description: English: Sample 25 mm × 25 mm × 140 mm PbF2 crystals (bare and wrapped in Millipore paper) are pictured together with a 16-channel monolithic Hamamatsu SiPM.
context_page_description: Muon g−2 is a particle physics experiment at Fermilab to measure the anomalous magnetic dipole moment of a muon to a precision of 0.14 ppm, which will be a sensitive test of the Standard Model. It might also provide evidence of the existence of entirely new particles.
  The muon, like its lighter sibling the electron, acts like a spinning magnet. The parameter known as the "g-factor" indicates how strong the magnet is and the rate of its gyration. The value of g is slightly larger than 2, hence the name of the experiment. This difference from 2 is caused by higher-order contributions from quantum field theory. In measuring g−2 with high precision and comparing its value to the theoretical prediction, physicists will discover whether the experiment agrees with theory. Any deviation would point to as yet undiscovered subatomic particles that exist in nature.
  The three data-taking periods have been completed, with preparations for Run-4 currently ongoing. The data analysis is still ongoing as of July 2020.
context_section_description: Central to the experiment is a 50-foot (15 m)-diameter superconducting magnet with an exceptionally uniform magnetic field. This was transported, in one piece, from Brookhaven in Long Island, New York, to Fermilab in the summer of 2013. The move traversed 3,200 miles over 35 days, mostly on a barge down the East Coast and through Mobile, Alabama to the Tennessee–Tombigbee Waterway and then briefly on the Mississippi. The initial and final legs were on a special truck traveling closed highways at night.
caption: Sample 25 mm × 25 mm × 140 mm PbF2 crystals (bare and wrapped in Millipore paper) are pictured together with a 16-channel monolithic Hamamatsu SiPM.
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