Related papers: Precision muon lifetime and capture experiments at…
The radiative muon capture(RMC) on a proton is analyzed by means of heavy baryon chiral perturbation theory. The emitted photon energy spectrum is calculated and compared with the experimental data by taking the spin sum on the muonic atom…
The Muon $(g-2)$ experiment, E821, at the Brookhaven AGS has the goal to measure the muon anomalous magnetic moment to a relative accuracy of $\pm 3.5 \times 10^{-7}$. A superferric 14 m diameter storage ring has been constructed and an…
Elementary particle physics is a fascinating field of modern physics investigating the basic constituents of matter and their interactions. In the experiments large accelerators and very sophisticated detector systems are usually used.…
A simple matching procedure is proposed to extract constraints on effective meson theories. In this way, a QCD prediction for the pion decay constant is found, F(pi)=2 m(pi)/pi, i.e. approximately 90MeV. The same procedure also determines…
The muon (g-2) experiment at Brookhaven National Laboratory has measured the anomalous magnetic moment of the positive muon with a precision of 0.7 ppm. This paper presents that result, concentrating on some of the important experimental…
Traditional analysis of $g=2(1+\kappa )$ experiments for charged leptons use a classical spin vector picture. For muons, we here employ a more exact Dirac quantum four component spinor theory. Survival probabilities (including wave packet…
We compute the muon capture on deuteron in the doublet hyperfine state for a variety of nuclear interactions and consistent nuclear currents. Our analysis includes a detailed examination of the theoretical uncertainties coming from…
A higher precision measurement of the anomalous g value, a_mu = (g-2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron, based on data collected in the year 2000. The result a_{mu^+} = 11 659…
The lifetime of the metastable 3P2 state of neon has been determined to 14.70(13) s (decay rate 0.06801(62) 1/s) by measuring the decay in fluorescence of an ensemble of Ne-20 atoms trapped in a magneto-optical trap (MOT). Due to low…
The neutron lifetime, $\tau$ = 880.2 $\pm$ 1.0 sec , is an important parameter for particle physics and cosmology. There is, however, an 8.4 sec (4.0$\,\sigma$) deviation between the measured value of the neutron lifetime using two methods…
Weak capture in muonic hydrogen ($\mu$H) as a probe of the chiral properties and nucleon structure predictions of Quantum Chromodynamics (QCD) is reviewed. A recent determination of the axial-vector charge radius squared, $r_A^2(z\; {\rm…
A measurement is presented of the neutron production rate in lead by high energy cosmic-ray muons at a depth of 2850 m water equivalent (w.e.) and a mean muon energy of 260 GeV. The measurement exploits the delayed coincidences between…
The MuCap experiment is a high-precision measurement of the rate for the basic electroweak process of muon capture, mu- + p -> n + nu . The experimental approach is based on an active target consisting of a time projection chamber (TPC)…
Electroweak radiative corrections to muon capture on nuclei are computed and found to be sizable. They enhance the capture rates for hydrogen and helium by 2.8% and 3.0% respectively. As a result, the value of the induced pseudoscalar…
The Muon $g-2$ experiment at Fermilab aims to measure the muon anomalous magnetic moment with an unprecedented precision of 140 parts per billion (ppb). Data collection concluded in June 2023, and analysis of the largest dataset (2021-2023)…
Several recent studies performed on constraints of a fourth generation of quarks and leptons suffer from the ad-hoc assumption that 3 x 3 unitarity holds for the first three generations in the neutrino sector. Only under this assumption one…
The lifetime measurement of pi+pi- atoms (A2pi) with 10% precision provides in a model independent way the difference between the S-wave pion-pion scattering lengths for isospin 0 and 2, |a0 -a2|, with 5% accuracy. The scattering lengths a0…
The anomalous magnetic moment (g-2) of the muon was measured with a precision of 0.54 ppm in Experiment 821 at Brookhaven National Laboratory. A difference of 3.2 standard deviations between this experimental value and the prediction of the…
Background: A muonic atom, composed of a negative muon and an atomic nucleus, undergoes two primary decay processes: muon-electron decay and muon nuclear capture. The branching ratio between these two processes can be determined from the…
The ratio of the \Lambda b baryon lifetime to that of the B0 meson is measured using 1.0/fb of integrated luminosity in 7 TeV center-of-mass energy pp collisions at the LHC. The \Lambda b baryon is observed for the first time in the decay…