Related papers: On the Precise Determination of the Fermi Coupling…
Over 40 years after the calculation of the 1-loop QED corrections to the muon lifetime, new theoretical developments have made it possible to obtain an analytic expression for the complete 2-loop QED contributions in the Fermi theory. The…
The complete 2-loop quantum electrodynamic corrections to the muon lifetime are calculated in the Fermi theory. The exact result for the effects of virtual and real photons, virtual electrons, muons as well as e+e- pair creation is Delta…
The complete 2-loop QED contributions to the muon lifetime have been calculated analytically in the Fermi theory. The exact result for the effects of virtual and real photons, virtual electrons, muons and hadrons as well as e+e- pair…
The muLan experiment at the Paul Scherrer Institute will measure the lifetime of the positive muon with a precision of 1 ppm, giving a value for the Fermi coupling constant G_F at the level of 0.5 ppm. Meanwhile, by measuring the observed…
The Fermi constant ($G_F$) is extremely well measured through the muon lifetime, defining one of the key fundamental parameters in the Standard Model (SM). Therefore, to search for physics beyond the SM (BSM) via $G_F$, the constraining…
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, tau_mu = 2.197013(24)…
The Fermi Constant, G_F, describes the strength of the weak force and is determined most precisely from the mean life of the positive muon, tau_mu. Advances in theory have reduced the theoretical uncertainty on G_F as calculated from tau_mu…
An initial measurement of the lifetime of the positive muon to a precision of 16 parts per million (ppm) has been performed with the FAST detector at the Paul Scherrer Institute. The result is tau_mu = 2.197083 (32) (15) microsec, where the…
The MuLan collaboration has measured the lifetime of the positve muon to a precision of 1.0 parts per million. The Fermi constant is determined to a precision of 0.6 parts per million.
An experiment is proposed for a record-breaking measurement of the world Fermi constant during the decay of a positive muon. Using the GEANT programs, an analysis of all systematic errors was performed. It is shown that the experimental…
The Fermi constant, G_F, describes the strength of the weak force and is determined most precisely from the mean life of the positive muon, tau_mu. Advances in theory have reduced the theoretical uncertainty on G_F as calculated from tau_mu…
We report a measurement of the positive muon lifetime to a precision of 1.0 parts per million (ppm); it is the most precise particle lifetime ever measured. The experiment used a time-structured, low-energy muon beam and a segmented plastic…
We present a detailed report of the method, setup, analysis and results of a precision measurement of the positive muon lifetime. The experiment was conducted at the Paul Scherrer Institute using a time-structured, nearly 100%-polarized,…
The MuLan experiment will measure the lifetime of the positive muon to 1ppm. Within the Standard Model framework, this will permit a determination of the Fermi Constant to 0.5ppm. I present an update on our progress and achievements to…
The FAC, PMS, and BLM optimization methods are applied to the QED corrections to the muon lifetime in the Fermi V-A theory. The FAC and PMS scales are close to m_e, while the BLM scale nearly concides with the geometric average \sqrt{m_e…
We discuss two precision experiments which will measure fundamental weak interaction parameters: MuLAN's goal is the measurement of the positive muon lifetime to 1 ppm, which will in turn determine the Fermi coupling constant G_F to 0.5 ppm…
We survey a new generation of precision muon lifetime experiments. The goal of the MuCap experiment is a determination of the rate for muon capture on the free proton to 1 percent, from which the induced pseudoscalar form factor $g_P$ of…
We report results from the MuLan measurement of the positive muon lifetime. The experiment was conducted at the Paul Scherrer Institute using a time-structured surface muon beam and a segmented plastic scintillator array. Two different…
We present an introduction to the MuLAN and MuCAP experiments at PSI, which aim at high precision determinations of two fundamental Weak Interactions parameters: the Fermi constant $G_{F}$ and the induced pseudoscalar form factor $g_{p}$,…
An independent result for the two loop fermionic contributions to the muon lifetime in the Standard Model is obtained. Deviations are found with respect to \cite{Freitas:2000gg}, which result in a shift of the W boson mass by approximately…