Author
F. Krienen
Bio: F. Krienen is an academic researcher from CERN. The author has contributed to research in topics: Spark chamber & Muon. The author has an hindex of 15, co-authored 26 publications receiving 891 citations.
Topics: Spark chamber, Muon, Neutrino, Storage ring, Stochastic cooling
Papers
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TL;DR: In this article, the anomalous magnetic moments of positive and negative muons were found to be aμ+ = 1165911(11) × 10−9 and aμ− = 1165937(12) × 11−9 giving an average value for muons of aμ= 1165924(8.5)×10−19e · cm.
332 citations
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TL;DR: The anomalous g −factor a ≡ ( g −2)/2 has been measured for muons of both charges in the Muon Storage Ring at CERN as mentioned in this paper, which is very close to the most recent theoretical prediction 1165921(10) × 10 −9.
72 citations
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TL;DR: In this article, new measurements of the electric dipole moment muons of both charges have been made in the Muon Storage Ring at CERN, and it is concluded, at 95% confidence level, that mod Dmu mod
Abstract: New measurements of the electric dipole moment muons of both charges have been made in the Muon Storage Ring at CERN. The values found are Dmu +=(8.6+or-4.5)*10-19 e cm Dmu -=(0.8+or-4.3)*10-19 e cm (errors are of one standard deviation). It is concluded, at 95% confidence level, that mod Dmu mod
57 citations
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CERN1
TL;DR: In this paper, a general description of the CERN ICE electron cooling experiment is given, and the storage ring and the design and realisation of the cooling apparatus (electron gun and collector, the vacuum system, the magnetic system, beam diagnostics, high voltage stabilisation) are discussed.
50 citations
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TL;DR: The 2010 self-consistent set of values of the basic constants and conversion factors of physics and chemistry recommended by the Committee on Data for Science and Technology (CODATA) for international use is presented in this article.
Abstract: This paper gives the 2010 self-consistent set of values of the basic constants and conversion factors of physics and chemistry recommended by the Committee on Data for Science and Technology (CODATA) for international use. The 2010 adjustment takes into account the data considered in the 2006 adjustment as well as the data that became available from 1 January 2007, after the closing date of that adjustment, until 31 December 2010, the closing date of the new adjustment. Further, it describes in detail the adjustment of the values of the constants, including the selection of the final set of input data based on the results of least-squares analyses. The 2010 set replaces the previously recommended 2006 CODATA set and may also be found on the World Wide Web at physics.nist.gov/constants.
2,770 citations
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Brookhaven National Laboratory1, University of Minnesota2, Boston University3, University of Illinois at Urbana–Champaign4, Yale University5, Budker Institute of Nuclear Physics6, Heidelberg University7, Tokyo Institute of Technology8, University of Groningen9, Tokyo University of Science10, Cornell University11, Fairfield University12
TL;DR: In this article, the authors presented the final report from a series of precision measurements of the muon anomalous magnetic moment, a(mu)=(g-2)/2.54 ppm, which represents a 14-fold improvement compared to previous measurements at CERN.
Abstract: 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)=11659208.0(5.4)(3.3)x10(-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, approximate to 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.
2,207 citations
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TL;DR: This review summarizes both the theoretical frameworks for tests of Lorentz invariance and experimental advances that have made new high precision tests possible.
Abstract: Motivated by ideas about quantum gravity, a tremendous amount of effort over the past decade has gone into testing Lorentz invariance in various regimes. This review summarizes both the theoretical frameworks for tests of Lorentz invariance and experimental advances that have made new high precision tests possible. The current constraints on Lorentz violating effects from both terrestrial experiments and astrophysical observations are presented.
1,008 citations
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TL;DR: In this article, the authors present a review of the status of the theoretical prediction and in particular discuss the role of the hadronic vacuum polarization effects and hadronic light-by-light scattering correction, including a new evaluation of the dominant pion exchange contribution.
945 citations
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TL;DR: The anomalous magnetic moment of the negative muon has been measured to a precision of 0.7 ppm (ppm) at the Brookhaven Alternating Gradient Synchrotron, and is over an order of magnitude more precise than the previous measurement.
Abstract: We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g-2 Experiment for the positive muon magnetic anomaly a_{μ}≡(g_{μ}-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ω_{a} between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ω[over ˜]_{p}^{'} in a spherical water sample at 34.7 °C. The ratio ω_{a}/ω[over ˜]_{p}^{'}, together with known fundamental constants, determines a_{μ}(FNAL)=116 592 040(54)×10^{-11} (0.46 ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both μ^{+} and μ^{-}, the new experimental average of a_{μ}(Exp)=116 592 061(41)×10^{-11} (0.35 ppm) increases the tension between experiment and theory to 4.2 standard deviations.
932 citations