ﻻ يوجد ملخص باللغة العربية
We present the final report from a series of precision measurements of the muon anomalous magnetic moment, a_mu = (g-2)/2. The details of the experimental method, apparatus, data taking, and analysis are summarized. Data obtained at Brookhaven National Laboratory, using nearly equal samples of positive and negative muons, were used to deduce a_mu(Expt) = 11 659 208.0(5.4)(3.3) x 10^-10, where the statistical and systematic uncertainties are given, respectively. The combined uncertainty of 0.54 ppm represents a 14-fold improvement compared to previous measurements at CERN. The standard model value for a_mu includes contributions from virtual QED, weak, and hadronic processes. While the QED processes account for most of the anomaly, the largest theoretical uncertainty, ~0.55 ppm, is associated with first-order hadronic vacuum polarization. Present standard model evaluations, based on e+e- hadronic cross sections, lie 2.2 - 2.7 standard deviations below the experimental result.
We present the first results of the Fermilab Muon g-2 Experiment for the positive muon magnetic anomaly $a_mu equiv (g_mu-2)/2$. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy
We report on a precision measurement of the cross section for the reaction $e^+e^-topi^+pi^-$ in the mass range $0.30<M_{pipi}<1.00$ GeV with the initial state radiation (ISR) method, using 817 pb$^{-1}$ of data at $e^+e^-$ center-of-mass energies ne
The muon anomalous magnetic moment measurement, when compared with theory, can be used to test many extensions to the standard model. The most recent measurement made by the Brookhaven E821 Collaboration reduces the uncertainty on the world average o
A new QCD sum rule determination of the leading order hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon, $a_{mu}^{rm hvp}$, is proposed. This approach combines data on $e^{+}e^{-}$ annihilation into hadrons, pertu
The BaBar collaboration has an extensive program of studying hadronic cross sections in low-energy e+e- collisions, accessible via initial-state radiation. Our measurements allow significant improvements in the precision of the predicted value of the