2,317 research outputs found
Finite Mass Effect on Two Photon Processes in Hydrogenic Systems: Effective Scalar Photon Interaction
We consider a hydrogenic system with a nucleus of finite mass. The coupling
of the radiation field to the center of mass motion gives rise to an effective
scalar type coupling. This induced scalar photon interaction emerges as a
correction in competition with the usual multipole interactions. This effect is
particularly important in positronium where the electric quadrupole interaction
is totally suppressed. We illustrate this effect with the two-photon decay of
metastable hydrogenic systems.Comment: 12 pages, Latex, no figure. Version to appear in Phys. Lett.
Further implications of the Bessis-Moussa-Villani conjecture
We find further implications of the BMV conjecture, which states that for
hermitian matrices A and B, the function Tr exp(A - t B) is the Laplace
transform of a positive measure.Comment: LaTeX, 8 page
In support of shorter hospital stays for selected highârisk obstetric patients
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135274/1/ijgo105.pd
Gauge Invariant Geometric Variables For Yang-Mills Theory
In a previous publication [1], local gauge invariant geometric variables were
introduced to describe the physical Hilbert space of Yang-Mills theory. In
these variables, the electric energy involves the inverse of an operator which
can generically have zero modes, and thus its calculation is subtle. In the
present work, we resolve these subtleties by considering a small deformation in
the definition of these variables, which in the end is removed. The case of
spherical configurations of the gauge invariant variables is treated in detail,
as well as the inclusion of infinitely heavy point color sources, and the
expression for the associated electric field is found explicitly. These
spherical geometries are seen to correspond to the spatial components of
instanton configurations. The related geometries corresponding to Wu-Yang
monopoles and merons are also identified.Comment: 21 pp. in plain TeX. Uses harvmac.te
Proton-Induced Background Studies for a Satellite Gamma-Ray Experiment
This work was supported by the National Science Foundation Grant NSF PHY 78-22774 A02 & A03 and by Indiana Universit
Combined effect of coherent Z exchange and the hyperfine interaction in atomic PNC
The nuclear spin-dependent parity nonconserving (PNC) interaction arising
from a combination of the hyperfine interaction and the coherent,
spin-independent, PNC interaction from Z exchange is evaluated using many-body
perturbation theory. For the 6s-7s transition in 133Cs, we obtain a result that
is about 40% smaller than that found previously by Bouchiat and Piketty [Phys.
Lett. B 269, 195 (1991)]. Applying this result to 133Cs, leads to an increase
in the experimental value of nuclear anapole moment and exacerbates differences
between constraints on PNC meson coupling constants obtained from the Cs
anapole moment and those obtained from other nuclear parity violating
experiments. Nuclear spin-dependent PNC dipole matrix elements, including
contributions from the combined weak-hyperfine interaction, are also given for
the 7s-8s transition in 211Fr and for transitions between ground-state
hyperfine levels in K, Rb, Cs, Ba+, Au, Tl, Fr, and Ra+.Comment: Revtex4 preprint 19 pages 4 table
Studies on Hypoxia: XII. Detrimental Effects of Synthetic Polyribonucleotides on Epiphyseal Plates of Rats Exposed to Hypoxia
The effect of different doses of polyadenylic and polyuridylic acids (poly A:U) was studied in control rats and in rats exposed to hypoxia. In the control rats, administration of different doses of poly A:U did not change the thickness of the epiphyseal plate or increase the incorporation of 3H-phenylalanine as judged using radioautography. Rats exposed to hypoxia showed a significant dose-related reduction in the thickness of the epiphyseal plate and 3H-phenylalanine incorporation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67926/2/10.1177_00220345760550041701.pd
Atom gratings produced by large angle atom beam splitters
An asymptotic theory of atom scattering by large amplitude periodic
potentials is developed in the Raman-Nath approximation. The atom grating
profile arising after scattering is evaluated in the Fresnel zone for
triangular, sinusoidal, magneto-optical, and bichromatic field potentials. It
is shown that, owing to the scattering in these potentials, two
\QTR{em}{groups} of momentum states are produced rather than two distinct
momentum components. The corresponding spatial density profile is calculated
and found to differ significantly from a pure sinusoid.Comment: 16 pages, 7 figure
Recommended from our members
DOE transporation programs - computerized techniques
One of the major thrusts of the transportation programs at the Oak Ridge National Laboratory has been the development of a number of computerized transportation programs and data bases. The U.S. Department of Energy (DOE) is supporting these efforts through the Transportation Technology Center at Sandia National Laboratories and the Tranportation Operations and Traffic Management (TOTM) organization at DOE Headquarters. Initially this project was centered upon research activities. However, since these tools provide traffic managers and key personnel involved in preshipment planning with a unique resource for ensuring that the movement of radioactive materials can be properly accomplished, additional interest and support is coming from the operational side of DOE. The major accomplishments include the development of two routing models (one for rail shipments and the other for highway shipments), an emergency response assistance program, and two data bases containing pertinent legislative and regulatory information. This paper discusses the mose recent advances in, and additions to, these computerized techniques and provides examples of how they are used
- âŠ