The Muon g − 2 experiment at Fermilab
Precision measurements of the anomalous magnetic moment of the muon aμ are a stringent test of the Standard Model. The last measurement of aμ at Brookhaven National Laboratory (BNL) differs from the Standard Model prediction by 3-4σ: a possible indication of new physics. A successor to that experiment has been constructed at Fermilab, with the aim of reducing the experimental uncertainty by a factor of four to 140 ppb. The measurement technique continues to use the storage ring concept from BNL, with muons circulating in a highly uniform magnetic dipole field. The spin precession frequency is extracted by analysing the modulation of the rate of higher-energy positrons from muon decays, which are detected by 24 calorimeters around the inside of the ring. Compared to the previous experiment, significant improvements have been made in the areas of muon beam preparation, storage ring hardware, field measuring equipment, and detector and electronics systems. In these proceedings, I report on the status of the experiment as of June 2018, presenting an overview of the experiment’s progress, some initial data from the first run, and the anticipated timeline for a new result.
KeywordsMuon Anomalous magnetic moment Test of standard model
This work was supported in part by Fermilab and the US DOE Office of High Energy Physics.
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