The new FNAL muon g-2 experiment

Abstract

The most recent measurement of the anomalous magnetic moment of the muon by the BNL E821 experiment differs from the Standard Model prediction by approximately 3.5 standard deviations. This may be indicative of new physics beyond the Standard Model or a statistical fluctuation. In this talk a new experiment, FNAL E989, is described that is seeking to improve on the precision of the BNL measurement by more than a factor of 4 and so resolve this issue. This precision is sufficient to establish evidence for new physics beyond the Standard Model at more than 5 σ should the present anomaly be confirmed.

Alignment of the straw tracking detectors for the Fermilab Muon $g-2$ experiment and systematic studies for a muon electric dipole moment measurement

“…The principal goal of the Fermilab Muon g − 2 experiment is the reduction of the experimental uncertainty on the measurement of a µ , as compared with the BNL experiment, using a measurement strategy similar to the one at the BNL [1]. This reduction in the uncertainty on a µ will be achieved via reductions in the statistical uncertainty due to the use of the Fermilab muon beam [16], and the systematic uncertainty due to improvements in the detectors, such as the in-vacuum tracking detectors [17], and more finely segmented calorimeters [18], a better field uniformity [19],…”

“…(B.17) The action of an anticlockwise rotation is given by φ − x m sin φ z m sin φ + x m cos φ φ − x m sin φ + z centre z m sin φ + x m cos φ + x centre   . (B.19)The equation for a residual, under a 2D rotation, can be written using Equation (B 19),. and is given byr = DCA(z(φ), x(φ), m, c) − r = |c + mz(φ) − x(φ)| m 2 + 1 − r = = |c + mz m cos φ − mx m sin φ + mz centre − z m sin φ − x m cos φ − x centre | m expressionfor ∂r ∂φ in terms of global and local parameters is used ∂r ∂φ = ∂DCA(z(φ), x(φ), m, c) ∂φ .…”

Review of recent Leading-Order Hadronic Vacuum Polarization calculation

“…On the other hand, the uncertainty of the direct measurement (dominated by the statistical precision) is now larger than the total uncertainty of the SM predictions. Two new g−2 experiments from Fermilab and J-PARC are being built and an error reduction by a factor of 4 is expected from these experiments in a few years from now [37].…”