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 State of the art in the determination of the fine structure constant: test of Quantum Electrodynamics and determination of h/mu

2013 ◽  
Vol 525 (7) ◽  
pp. 484-492 ◽  
Author(s):  
Rym Bouchendira ◽  
Pierre Cladé ◽  
Saida Guellati-Khélifa ◽  
Francois Nez ◽  
Francois Biraben
Keyword(s):  
Fine Structure ◽  
Quantum Electrodynamics ◽  
State Of The Art ◽  
Structure Constant ◽  
Fine Structure Constant

scholarly journals New Determination of the Fine Structure Constant and Test of the Quantum Electrodynamics

2011 ◽  
Vol 106 (8) ◽  
Author(s):  
Rym Bouchendira ◽  
Pierre Cladé ◽  
Saïda Guellati-Khélifa ◽  
François Nez ◽  
François Biraben
Keyword(s):  
Fine Structure ◽  
Quantum Electrodynamics ◽  
Structure Constant ◽  
Fine Structure Constant

Precision measurements of fine and hyperfine structure in lithium I and II

2005 ◽  
Vol 83 (4) ◽  
pp. 327-337 ◽  
Author(s):  
W A van Wijngaarden
Keyword(s):  
Fine Structure ◽  
Quantum Electrodynamics ◽  
Nuclear Charge ◽  
Structure Constant ◽  
Precision Measurements ◽  
Fine Structure Constant ◽  
Recent Measurement ◽  
Charge Radii ◽  
Fine And Hyperfine Structure

Recent advances in modeling Li I and II in conjunction with improved experimental techniques have enabled precise tests of quantum electrodynamics. For Li+, the hyperfine intervals of the 1s2s 3S1 and 1s2p 3P0,1,2 states are in excellent agreement with theory. A recent measurement of the 1s2p 3P1,2 fine-structure interval also agrees well with the calculated value and resolves a discrepancy found by two prior experiments. For neutral lithium, discrepancies exist among the results of various experiments for the 6,7Li D1 isotope shift and the 2P fine structure. However, all of the fine-structure measurements are several MHz larger than the theoretical value. Prospects for future experiments to improve the determination of the fine-structure constant and the relative 6,7Li nuclear charge radii are discussed. PACS Nos.: 32.10.Fn, 31.30.Gs, 42.62.Fi

scholarly journals New determination of the fine structure constant and test of the quantum electrodynamics

2012 ◽  
Author(s):  
Rym Bouchendira ◽  
Pierre Cladé ◽  
Saïda Guellati-Khélifa ◽  
François Nez ◽  
François Biraben
Keyword(s):  
Fine Structure ◽  
Quantum Electrodynamics ◽  
Structure Constant ◽  
Fine Structure Constant

Toward a determination of the fine structure constant at LNE by means of a new Thompson–Lampard calculable capacitorThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010.

2011 ◽  
Vol 89 (1) ◽  
pp. 169-176 ◽  
Author(s):  
P. Gournay ◽  
O. Thévenot ◽  
L. Dupont ◽  
J. M. David ◽  
F. Piquemal
Keyword(s):  
Fine Structure ◽  
Quantum Electrodynamics ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Current Development ◽  
Atomic Systems ◽  
International Conference ◽  
New Si ◽  
Cross Capacitor

This paper reports on the current development of a new Thompson–Lampard calculable capacitor at LNE. The goal is to determine the von Klitzing constant RK at a significant level of uncertainty of about one part in 108. The comparison with other accurate measurements of h/e2 serves as a relevant test of validity of the theory predicting RK = h/e2, a decisive issue within the context of the new SI. Conversely, assuming that this relation is exact, the measurement of RK and thus that of the fine structure constant α can be used for testing quantum electrodynamics theory. The mechanical structure of the new LNE calculable cross capacitor has been designed and a new set of electrodes has been fabricated. The assembling of the calculable capacitor is in progress.

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