1,155 research outputs found
Self-Energy Correction to the Bound-Electron g Factor of P States
The radiative self-energy correction to the bound-electron g factor of 2P_1/2
and 2P_3/2 states in one-electron ions is evaluated to order alpha (Z alpha)^2.
The contribution of high-energy virtual photons is treated by means of an
effective Dirac equation, and the result is verified by an approach based on
long-wavelength quantum electrodynamics. The contribution of low-energy virtual
photons is calculated both in the velocity and in the length gauge and gauge
invariance is verified explicitly. The results compare favorably to recently
available numerical data for hydrogenlike systems with low nuclear charge
numbers.Comment: 8 pages, RevTe
Observation of Spin Flips with a Single Trapped Proton
Radio-frequency induced spin transitions of one individual proton are
observed for the first time. The spin quantum jumps are detected via the
continuous Stern-Gerlach effect, which is used in an experiment with a single
proton stored in a cryogenic Penning trap. This is an important milestone
towards a direct high-precision measurement of the magnetic moment of the
proton and a new test of the matter-antimatter symmetry in the baryon sector
One more reason to learn a new language: Testing academic self-efficacy transfer at junior high school
The powerful role of self-efficacy within human development broadly, and in education specifically, is widely acknowledged. Less is understood about how self-efficacy might transfer between domains of varying conceptual distance. The current study examines academic self-efficacy in three domains (mathematics, Japanese and foreign language) across students’ first year at junior high school. Two studies were conducted each including three school (study-A: n=480; study-B: n=398) to support a test and retest of the differences and inter-relationships across this critical period of adjustment. Difference testing presented a general pattern of significant small declines in students’ self-efficacy for all three subjects. Longitudinal latent analyses indicated a consistent moderate effect from foreign language self-efficacy to native language self-efficacy. The pattern of declines, while consistent with research in Western contexts is a source of concern. The transfer of self-efficacy from foreign to native language learning has educational and broad theoretical implications.
Universality of Leading Relativistic Corrections to Bound State Gyromagnetic Ratios
We discuss the leading relativistic (nonrecoil and recoil) corrections to
bound state -factors of particles with arbitrary spin. These corrections are
universal for any spin and depend only on the free particle gyromagnetic
ratios. We explain the physical reasons behind this universality.Comment: 10 pp., based on talks given at the Gribov-80 Memorial Workshop,
ICTP, Trieste, Italy, May 2010 and at PSAS 2010 workshop, Les Houches, June
2010. To be published in the Gribov-80 Proceedings and in Can. J. Phy
A pandemic lesson for global lung diseases: exacerbations are preventable.
A dramatic global reduction in the incidence of common seasonal respiratory viral infections has resulted from measures to limit the transmission of SARS2-Cov-19 during the pandemic . This has been accompanied by falls reaching 50% internationally in the incidence of acute exacerbations of pre-existing chronic respiratory diseases that include asthma, Chronic Obstructive Pulmonary Disease (COPD) and Cystic Fibrosis (CF). At the same time, the incidence of acute bacterial pneumonia and sepsis has fallen steeply world-wide. Such findings demonstrate the profound impact of common respiratory viruses on the course of these global illnesses. Reduced transmission of common respiratory bacterial pathogens and their interactions with viruses appear also as central factors. This review summarises pandemic changes in exacerbation rates of asthma, COPD, Cystic Fibrosis (CF) and pneumonia. We draw attention to the substantial body of knowledge about respiratory virus infections in these conditions, and that it has not yet translated into clinical practice. Now the large-scale of benefits that could be gained by managing these pathogens is unmistakable, we suggest the field merits substantial academic and industrial investment. We consider how pandemic-inspired measures for prevention and treatment of common infections should become a cornerstone for managing respiratory diseases. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Atomic and nuclear physics with stored particles in ion traps
Trapping and cooling techniques play an increasingly important role in many areas of science. This review concentrates on recent applications of ion traps installed at accelerator facilities to atomic and nuclear physics such as mass spectrometry of radioactive isotopes, weak interaction studies, symmetry tests, determination of fundamental constants, laser spectroscopy, and spectroscopy of highly-charged ions. In addition, ion traps are proven to be extremely efficient devices for (radioactive) ion beam manipulation as, for example, retardation, accumulation, cooling, beam cleaning, charge-breeding, and bunching
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