Testing fundamental interactions on the helium atom

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F17%3A10367394" target="_blank" >RIV/00216208:11320/17:10367394 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1103/PhysRevA.95.062510" target="_blank" >http://dx.doi.org/10.1103/PhysRevA.95.062510</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevA.95.062510" target="_blank" >10.1103/PhysRevA.95.062510</a>

Result language

angličtina

Original language name

Testing fundamental interactions on the helium atom

Original language description

We critically examine the current status of theoretical calculations of the energies, the fine structure, and the isotope shift of the lowest-lying states of helium, searching for unresolved discrepancies with experiments. Calculations are performed within the quantum electrodynamics expansion in powers of the fine structure constant a and the electron-to-nucleus mass ratio m/M. For energies, theoretical results are complete through orders alpha(6)m and alpha(6)m(2)/M, with the resulting accuracy ranging from 0.5 to 2 MHz for the n = 2 states. The fine-structure splitting of the 2(3) P state is predicted with a much better accuracy, 1.7 kHz, as a consequence of a calculation of the next-order alpha(7)m effect. An excellent agreement of the theoretical predictions with the recent measurements of the fine structure provides one of the best tests of the bound-state QED in few-electron systems. The isotope shift between He-3 and He-4 is treated with a subkilohertz accuracy, which allows for a high-precision determination of the differences of the nuclear charge radii delta r(2). Several such determinations, however, yield results that are in a 4 sigma disagreement with each other, which remains unexplained. Apart from this, we find no significant discrepancies between theory and experiment for the helium atom. A further calculation of the yet unknown alpha(7)m correction to energy levels will provide a sensitive test of universality in electromagnetic interactions of leptons by comparison of nuclear charge radii obtained by the helium and muonic helium spectroscopy.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10300 - Physical sciences

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Physical Review A

ISSN

2469-9926

e-ISSN

—

Volume of the periodical

95

Issue of the periodical within the volume

6

Country of publishing house

US - UNITED STATES

Number of pages

8

Pages from-to

—

UT code for WoS article

000404461300005

EID of the result in the Scopus database

—