13,426 research outputs found
Calculation of Hydrogenic Bethe Logarithms for Rydberg States
We describe the calculation of hydrogenic (one-loop) Bethe logarithms for all
states with principal quantum numbers n <= 200. While, in principle, the
calculation of the Bethe logarithm is a rather easy computational problem
involving only the nonrelativistic (Schroedinger) theory of the hydrogen atom,
certain calculational difficulties affect highly excited states, and in
particular states for which the principal quantum number is much larger than
the orbital angular momentum quantum number. Two evaluation methods are
contrasted. One of these is based on the calculation of the principal value of
a specific integral over a virtual photon energy. The other method relies
directly on the spectral representation of the Schroedinger-Coulomb propagator.
Selected numerical results are presented. The full set of values is available
at quant-ph/0504002.Comment: 10 pages, RevTe
Is Job Enrichment Really Enriching?
This study uses a survey of Canadian workers with rich, matched data on job characteristics to examine whether “enriched” job design, with features like quality circles, feedback, suggestion programs, and task teams, affects job satisfaction. We identify two competing hypotheses on the relationship between enriched jobs and job satisfaction. The “motivation hypothesis,” implies that enrichment will generally increase satisfaction and the “intensification hypothesis,” implies that enrichment may decrease satisfaction by increasing the intensity and scope of work. Our results show that several forms of enrichment, specifically suggestion programs, information sharing, task teams, quality circles and training, raise satisfaction. Therefore we argue that the data support the motivation hypothesis. Partitioning the data by education level or union membership further supports this conclusion, while a direct test of the intensification hypothesis does not support the competing hypothesis.Job Satisfaction; Job Enrichment; Human Resource Practices
Fundamental constants and tests of theory in Rydberg states of one-electron ions
The nature of the theory of circular Rydberg states of hydrogenlike ions
allows highly-accurate predictions to be made for energy levels. In particular,
uncertainties arising from the problematic nuclear size correction which beset
low angular-momentum states are negligibly small for the high angular-momentum
states. The largest remaining source of uncertainty can be addressed with the
help of quantum electrodynamics (QED) calculations, including a new
nonperturbative result reported here. More stringent tests of theory and an
improved determination of the Rydberg constant may be possible if predictions
can be compared with precision frequency measurements in this regime. The
diversity of information can be increased by utilizing a variety of
combinations of ions and Ryberg states to determine fundamental constants and
test theory.Comment: 10 pages; LaTe
Portable, high intensity isotopic neutron source provides increased experimental accuracy
Small portable, high intensity isotopic neutron source combines twelve curium-americium beryllium sources. This high intensity of neutrons, with a flux which slowly decreases at a known rate, provides for increased experimental accuracy
Self-energy values for P states in hydrogen and low-Z hydrogenlike ions
We describe a nonperturbative (in Zalpha) numerical evaluation of the
one-photon electron self energy for 3P_{1/2}, 3P_{3/2}, 4P_{1/2} and 4P_{3/2}
states in hydrogenlike atomic systems with charge numbers Z=1 to 5. The
numerical results are found to be in agreement with known terms in the
expansion of the self energy in powers of Zalpha and lead to improved
theoretical predictions for the self-energy shift of these states.Comment: 3 pages, RevTe
- …