scholarly journals Anomalous magnetic moments of free and bound leptons

2006 ◽  
Vol 84 (6-7) ◽  
pp. 453-462 ◽  
Author(s):  
A Czarnecki ◽  
U D Jentschura ◽  
K Pachucki ◽  
V A Yerokhin
Keyword(s):  
Fine Structure ◽  
Magnetic Moments ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Theoretical Knowledge ◽  
Electron Mass ◽  
Fundamental Physical Constants ◽  
Free Electrons ◽  
Fundamental Physical

We review the theoretical knowledge of anomalous magnetic moments of free electrons and muons, and of electrons bound in hydrogenlike ions. We discuss applications of these observations in the determination of fundamental physical constants, the fine structure constant, the electron mass, and in searches for new interactions.PACS Nos.: 14.60.–z, 13.40.Em, 32.10.Dk

scholarly journals Speed of sound from fundamental physical constants

2020 ◽  
Vol 6 (41) ◽  
pp. eabc8662
Author(s):  
K. Trachenko ◽  
B. Monserrat ◽  
C. J. Pickard ◽  
V. V. Brazhkin
Keyword(s):  
Speed Of Sound ◽  
Structure Constant ◽  
Point Of View ◽  
Fine Structure Constant ◽  
Electron Mass ◽  
Large Set ◽  
Fundamental Physical Constants ◽  
Physical Constants ◽  
Dimensionless Constant ◽  
Fundamental Physical

Two dimensionless fundamental physical constants, the fine structure constant α and the proton-to-electron mass ratio mpme, are attributed a particular importance from the point of view of nuclear synthesis, formation of heavy elements, planets, and life-supporting structures. Here, we show that a combination of these two constants results in a new dimensionless constant that provides the upper bound for the speed of sound in condensed phases, vu. We find that vuc=α(me2mp)12, where c is the speed of light in vacuum. We support this result by a large set of experimental data and first-principles computations for atomic hydrogen. Our result expands the current understanding of how fundamental constants can impose new bounds on important physical properties.

scholarly journals New Limit on Space-Time Variations in the Proton-to-Electron Mass Ratio from Analysis of Quasar J110325-264515 Spectra

Symmetry ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 344
Author(s):  
T. D. Le
Keyword(s):  
Fine Structure ◽  
Structure Constant ◽  
Space Time ◽  
Fine Structure Constant ◽  
Electron Mass ◽  
Mass Ratio ◽  
Quasar Spectra ◽  
Time Variations ◽  
Using Data ◽  
The Universe

Astrophysical tests of current values for dimensionless constants known on Earth, such as the fine-structure constant, α , and proton-to-electron mass ratio, μ = m p / m e , are communicated using data from high-resolution quasar spectra in different regions or epochs of the universe. The symmetry wavelengths of [Fe II] lines from redshifted quasar spectra of J110325-264515 and their corresponding values in the laboratory were combined to find a new limit on space-time variations in the proton-to-electron mass ratio, ∆ μ / μ = ( 0.096 ± 0.182 ) × 10 − 7 . The results show how the indicated astrophysical observations can further improve the accuracy and space-time variations of physics constants.

scholarly journals Fundamental physics and the fine-structure constant

2017 ◽  
Vol 5 (2) ◽  
pp. 46 ◽  
Author(s):  
Michael Sherbon
Keyword(s):  
Fine Structure ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Electron Mass ◽  
Fundamental Constants ◽  
Mass Ratio ◽  
Fundamental Physics ◽  
Weak Force ◽  
Strong Force ◽  
Symmetry Principles

From the exponential function of Euler’s equation to the geometry of a fundamental form, a calculation of the fine-structure constant and its relationship to the proton-electron mass ratio is given. Equations are found for the fundamental constants of the four forces of nature: electromagnetism, the weak force, the strong force and the force of gravitation. Symmetry principles are then associated with traditional physical measures.

scholarly journals Precision spectroscopy of atomic helium

2020 ◽  
Vol 7 (12) ◽  
pp. 1818-1827
Author(s):  
Yu R Sun ◽  
Shui-Ming Hu
Keyword(s):  
Fine Structure ◽  
Quantum Electrodynamics ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Nuclear Charge Radius ◽  
Precision Spectroscopy ◽  
Structure Splitting ◽  
Three Body ◽  
Atomic Helium

Abstract Helium is a prototype three-body system and has long been a model system for developing quantum mechanics theory and computational methods. The fine-structure splitting in the 23P state of helium is considered to be the most suitable for determining the fine-structure constant α in atoms. After more than 50 years of efforts by many theorists and experimentalists, we are now working toward a determination of α with an accuracy of a few parts per billion, which can be compared to the results obtained by entirely different methods to verify the self-consistency of quantum electrodynamics. Moreover, the precision spectroscopy of helium allows determination of the nuclear charge radius, and it is expected to help resolve the ‘proton radius puzzle’. In this review, we introduce the latest developments in the precision spectroscopy of the helium atom, especially the discrepancies among theoretical and experimental results, and give an outlook on future progress.

scholarly journals Radiative Corrections for a Precision Determination of the Fine Structure Constant

2018 ◽  
Vol 179 ◽  
pp. 01023
Author(s):  
Luca Trentadue
Keyword(s):  
Fine Structure ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Radiative Corrections ◽  
Precision Determination

We discuss the implications of a new proposed approach to determine aHLOμ and αQED by using space-like kinematics.

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