Present status of the fine-structure frequencies of the 23P helium level

2005 ◽  
Vol 83 (4) ◽  
pp. 301-310 ◽  
Author(s):  
G Giusfredi ◽  
P Cancio Pastor ◽  
P De Natale ◽  
D Mazzotti ◽  
C de Mauro ◽  
...  
Keyword(s):  
Fine Structure ◽  
Present Status ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Helium Level

A new measurement of the fine-structure frequencies of the 23 P level in 4He is presented. The result for the largest interval 23 P0–23 P1 is 29 616 952.7(1.0) kHz, and 2 291 167.7(11.0) kHz for the smallest one, 23 P1–23 P2. Taking into account this new result, an agreement among different experiments at the 1 kHz level is found. Implications of this situation for the determination of the fine-structure constant α are discussed. PACS Nos.: 31.15.Pf, 31.30.Jv, and 32.10.Hq

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.

Accurate determination of the fine structure constant and test of QED

2012 ◽  
Author(s):  
Rym Bouchendira ◽  
Pierre Clade ◽  
Saida Guelatti-Khelifa ◽  
Francois Nez ◽  
Francois Biraben
Keyword(s):  
Fine Structure ◽  
Accurate Determination ◽  
Structure Constant ◽  
Fine Structure Constant

scholarly journals Recent results on hadron physics at KLOE-2

2019 ◽  
Vol 212 ◽  
pp. 04003
Author(s):  
Francesca Curciarello
Keyword(s):  
Fine Structure ◽  
Cross Section ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Hadron Physics ◽  
Light Mesons

The KLOE-2 experiment at the Frascati φ−factory ended its data-taking in March 2018 collecting more than 5 fb−1 at the φ peak. The new data sample, together with the KLOE one, corresponds to 2.4 ×1010 φ and 3.1×108 η meson events. It represents the largest sample ever collected at the φ peak in e+e− colliders, allowing to study light mesons with unprecedented statistics. Recent results obtained with KLOE data on hadron physics e.g. – measurement of the running of the fine structure constant below 1 GeV, the combination of hadron cross section measurements with determination of $ a_\mu ^{\pi \pi } $, the new preliminary η → π+π− limit, and progress in γγ studies – will be presented.

scholarly journals Measurement of the ratio and determination of the fine structure constant

2011 ◽  
Vol 12 (4) ◽  
pp. 379-386 ◽  
Author(s):  
Malo Cadoret ◽  
Estefania de Mirandés ◽  
Pierre Cladé ◽  
Saïda Guellati-Khélifa ◽  
François Nez ◽  
...  
Keyword(s):  
Fine Structure ◽  
Structure Constant ◽  
Fine Structure Constant
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