[en] The Fermilab Muon g-2 Experiment has a goal of measuring the muon anomalous magnetic moment to a precision of 140 ppb - a fourfold improvement over the 540 ppb precision obtained by the BNL Muon g-2 Experiment. Some muons in the storage ring will interact with material and undergo bremsstrahlung, emitting radiation and loosing energy. These so called lost muons will curl in towards the center of the ring and be lost, but some of them will be detected by the calorimeters. A systematic error will arise if the lost muons have a different average spin phase than the stored muons. Algorithms are being developed to estimate the relative number of lost muons, so as to optimize the stored muon beam. This study presents initial testing of algorithms that can be used to estimate the lost muons by using either double or triple detection coincidences in the calorimeters.

No abstract available

[en] We report a measurement of the positive muon lifetime to a precision of 1.0 ppm; it is the most precise particle lifetime ever measured. The experiment used a time-structured, low-energy muon beam and a segmented plastic scintillator array to record more than 2x10¹² decays. Two different stopping target configurations were employed in independent data-taking periods. The combined results give τ_μ⁺(MuLan)=2 196 980.3(2.2) ps, more than 15 times as precise as any previous experiment. The muon lifetime gives the most precise value for the Fermi constant: G_F(MuLan)=1.166 378 8(7)x10^-5 GeV^-2 (0.6 ppm). It is also used to extract the μ^-p singlet capture rate, which determines the proton's weak induced pseudoscalar coupling g_P.

[en] The mean life of the positive muon has been measured to a precision of 11 ppm using a low-energy, pulsed muon beam stopped in a ferromagnetic target, which was surrounded by a scintillator detector array. The result, τ_μ=2.197 013(24) μs, is in excellent agreement with the previous world average. The new world average τ_μ=2.197 019(21) μs determines the Fermi constant G_F=1.166 371(6)x10^-5 GeV^-2 (5 ppm). Additionally, the precision measurement of the positive-muon lifetime is needed to determine the nucleon pseudoscalar coupling g_P