scholarly journals Three-loop radiative-recoil corrections to hyperfine splitting in muonium

2005 ◽  
Vol 83 (4) ◽  
pp. 363-373 ◽  
Author(s):  
Michael I Eides ◽  
Howard Grotch ◽  
Valery A Shelyuto
Keyword(s):  
Experimental Data ◽  
Hyperfine Splitting ◽  
Theoretical Uncertainty ◽  
Invariant Sets ◽  
Mass Ratio ◽  
Gauge Invariant ◽  
Muon Mass ◽  
Long Time ◽  
Muonium Hyperfine ◽  
Leading Logarithm

We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium. These corrections are enhanced by the large logarithm of the electron–muon mass ratio. The leading logarithm-cubed and logarithm-squared contributions were obtained a long time ago. We calculate the single-logarithmic and nonlogarithmic contributions of order α3(m/M)EF generated by gauge invariant sets of diagrams with one- and two-loop polarization insertions in diagrams with two exchanged photons and radiative photons, and by diagrams with one-loop radiative photon insertions both in the electron and muon lines. The results of this paper constitute a next step in the implementation of the program of reduction of the theoretical uncertainty of hyperfine splitting below 10 Hz. They improve the theory of hyperfine splitting, and affect the value of the electron–muon mass ratio extracted from experimental data on the muonium hyperfine splitting.PACS Nos.: 12.20.Ds, 31.30.Jv, 32.10.Fn, 36.10.Dr

Hyperfine splitting in muonium and positronium

2016 ◽  
Vol 31 (28n29) ◽  
pp. 1645034 ◽  
Author(s):  
Michael I. Eides ◽  
Valery A. Shelyuto
Keyword(s):  
Hyperfine Splitting ◽  
Invariant Sets ◽  
Gauge Invariant ◽  
Photon Exchange ◽  
Two Photon

Calculation of hard three-loop corrections of order [Formula: see text] to hyperfine splitting in muonium and positronium is reviewed. All these contributions are generated by the graphs with photon, electron and/or muon loop radiative insertions in the two-photon exchange diagrams. We calculate contributions of six gauge invariant sets of diagrams.

scholarly journals Three-loop radiative corrections to Lamb shift and hyperfine splitting

2007 ◽  
Vol 85 (5) ◽  
pp. 509-519 ◽  
Author(s):  
Michael I Eides ◽  
Valery A Shelyuto
Keyword(s):  
Hyperfine Splitting ◽  
Lamb Shift ◽  
Polarization Operator ◽  
Invariant Sets ◽  
Radiative Corrections ◽  
Gauge Invariant ◽  
Electron Polarization ◽  
Electron Line

We consider three-loop radiative corrections to the Lamb shift and hyperfine splitting. Corrections of order α3(Zα)5m are the largest still unknown contributions to the Lamb shift in hydrogen. We calculate radiative corrections to the Lamb shift and hyperfine splitting generated by the diagrams with insertions of one radiative photon and electron polarization loops in the graphs with two external photons. We also obtain corrections generated by the gauge-invariant sets of diagrams with two reducible radiative photon insertions in the electron line and a polarization operator insertion in one of the radiative photons, and diagrams with two reducible radiative photon insertions in the electron line and a polarization operator insertion in one of the external photons. Corrections to the Lamb shift and hyperfine splitting generated by the diagrams with insertions of the three-loop one-particle reducible diagrams with radiative photons in the electron line are calculated in the Yennie gauge.PACS Nos.: 12.20.Ds, 31.30.Jv, 32.10.Fn, 36.10.Dr

Hard three-loop corrections to hyperfine splitting

2016 ◽  
Vol 31 (02n03) ◽  
pp. 1641030
Author(s):  
Michael I. Eides ◽  
Valery A. Shelyuto
Keyword(s):  
Hyperfine Splitting ◽  
Invariant Sets ◽  
Gauge Invariant ◽  
Photon Exchange ◽  
Two Photon

We consider hard three-loop nonlogarithmic corrections of order [Formula: see text] to hyperfine splitting in muonium and positronium. All these contributions are generated by the graphs with photon, electron and/or muon loop radiative insertions in the two-photon exchange diagrams. We calculate contributions of six gauge invariant sets of diagrams.

Interaction of Point Defects in Ice

1978 ◽  
Vol 21 (85) ◽  
pp. 115-122
Author(s):  
J. H. Bilgram ◽  
H. Gränicher
Keyword(s):  
Experimental Data ◽  
Dielectric Properties ◽  
Temperature Dependence ◽  
Point Defects ◽  
Low Frequency ◽  
Defect Concentration ◽  
Dielectric Measurements ◽  
Long Time ◽  
Nmr Techniques ◽  
Bjerrum Defect

AbstractThe interaction of point detects in ice has been neglected for a long time. Experimental data obtained from dielectric measurements on HF-doped crystals stimulated a new evaluation of the possibility of an interaction between Bjerrum defects and ions. In a previous paper it has been shown that this leads us to assume the existence of aggregates of Bjerrum defects and ions. In this paper these aggregates and Bjerrum defects are used to explain the dielectric properties of ice, especially the temperature dependence of the product of the high and low frequency conductivity σ0σ∞.The interaction of Bjerrum defects and impurity molecules leads to a dependence of the concentration of frenkel pairs on Bjerrum-defect concentration. At HF concentrations above the native Bjerrum-defect concentration the formation of a Frenkel pair is enhanced. This leads to the fast out-diffusion which has been studied in highly doped crystals by means of NMR techniques.

Investigation of logarithmic contributions in the electron-to-muon mass ratio to the shift of the S energy levels in the muonium atom

2003 ◽  
Vol 66 (5) ◽  
pp. 893-901 ◽  
Author(s):  
N. A. Boikova ◽  
S. V. Kleshchevskaya ◽  
Yu. N. Tyukhtyaev ◽  
R. N. Faustov
Keyword(s):  
Energy Levels ◽  
Mass Ratio ◽  
Muonium Atom ◽  
Muon Mass

scholarly journals On spin asymmetry in muon and tau decays

2018 ◽  
Vol 33 (32) ◽  
pp. 1850191
Author(s):  
A. B. Arbuzov ◽  
T. V. Kopylova ◽  
I. K. Sklyarov
Keyword(s):  
Charged Lepton ◽  
Spin Asymmetry ◽  
Second Order ◽  
Tau Leptons ◽  
Mass Ratio ◽  
Fermi Model ◽  
Tau Decays ◽  
Standard Formula ◽  
Leading Logarithm ◽  
Michel Parameters

The angular asymmetry in decays of polarized muons and tau leptons is discussed. Both the standard [Formula: see text] Fermi model and the general parametrization via Michel parameters are considered. Numerical importance of contributions suppressed by charged lepton mass ratio is underlined. Contribution of the second order QED correction is estimated in the leading logarithm approximation.

scholarly journals Ut vis sic tensio

2018 ◽  
Vol 45 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Giuseppe Saccomandi
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Elastic Strain ◽  
Strain Energy ◽  
Nonlinear Response ◽  
Solid Mechanics ◽  
Functional Form ◽  
Elastic Strain Energy ◽  
Strongly Nonlinear ◽  
Long Time

The mechanical properties of rubber-like materials have been offering an outstanding challenge to the solid mechanics community for a long time. The behaviour of such materials is quite difficult to predict because rubber self-organizes into mesoscopic physical structures that play a prominent role in determining their complex, history-dependent and strongly nonlinear response. In this framework one of the main problems is to find a functional form of the elastic strain-energy that best describes the experimental data in a mathematical feasible way. The aim of this paper is to give a survey of recent advances aimed at solving such a problem.

scholarly journals Double-well trap for charged microparticles

2021 ◽  
Vol 2103 (1) ◽  
pp. 012222
Author(s):  
Olga Kokorina ◽  
Vadim Rybin ◽  
Semyon Rudyi
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Strong Correlation ◽  
Paul Trap ◽  
Axial Position ◽  
Experimental Setup ◽  
Mass Ratio ◽  
Linear Paul Trap ◽  
Spatial Selection ◽  
Axial Density

Abstract We propose a double-well linear Paul trap for particle’s spatial selection according to the charge-to-mass ratio. To perform spatial selection we implemented an experimental setup that permits to detect particles’ positions in the double-well trap from three different view-points: top, front left, and front right. The setup gives an opportunity to monitor the particles’ axial density distribution in real-time. We have shown a strong correlation between axial position of separated localization areas and the DC voltages applied to the rod and end-cap electrodes. We have experimentally determined the critical localization parameters where double-well mode acquires for all the trapped charged microparticles. According to the experimental data and a numerical simulation a upper value of charge-to-mass ratio of the trapped microparticles was estimated.

Parallel Multi-Cycle LES of an Optical Pent-Roof DISI Engine Under Motored Operating Conditions

2017 ◽  
Author(s):  
Noah Van Dam ◽  
Wei Zeng ◽  
Magnus Sjöberg ◽  
Sibendu Som
Keyword(s):  
Experimental Data ◽  
Direct Injection ◽  
Operating Conditions ◽  
New Strategy ◽  
Long Time ◽  
Order Of Magnitude ◽  
Structure Index ◽  
Number Of Cycles ◽  
The Many ◽  
Direct Injection Spark Ignition

The use of Large-eddy Simulations (LES) has increased due to their ability to resolve the turbulent fluctuations of engine flows and capture the resulting cycle-to-cycle variability. One drawback of LES, however, is the requirement to run multiple engine cycles to obtain the necessary cycle statistics for full validation. The standard method to obtain the cycles by running a single simulation through many engine cycles sequentially can take a long time to complete. Recently, a new strategy has been proposed by our research group to reduce the amount of time necessary to simulate the many engine cycles by running individual engine cycle simulations in parallel. With modern large computing systems this has the potential to reduce the amount of time necessary for a full set of simulated engine cycles to finish by up to an order of magnitude. In this paper, the Parallel Perturbation Methodology (PPM) is used to simulate up to 35 engine cycles of an optically accessible, pent-roof Direct-injection Spark-ignition (DISI) engine at two different motored engine operating conditions, one throttled and one un-throttled. Comparisons are made against corresponding sequential-cycle simulations to verify the similarity of results using either methodology. Mean results from the PPM approach are very similar to sequential-cycle results with less than 0.5% difference in pressure and a magnitude structure index (MSI) of 0.95. Differences in cycle-to-cycle variability (CCV) predictions are larger, but close to the statistical uncertainty in the measurement for the number of cycles simulated. PPM LES results were also compared against experimental data. Mean quantities such as pressure or mean velocities were typically matched to within 5–10%. Pressure CCVs were under-predicted, mostly due to the lack of any perturbations in the pressure boundary conditions between cycles. Velocity CCVs for the simulations had the same average magnitude as experiments, but the experimental data showed greater spatial variation in the root-mean-square (RMS). Conversely, circular standard deviation results showed greater repeatability of the flow directionality and swirl vortex positioning than the simulations.

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