2,623 research outputs found
Composite Skyrme Model with Vector Mesons
We study the composite Skyrme model, proposed by Cheung and G\"{u}rsey,
introducing vector mesons in a chiral Lagrangian. We calculate the static
properties of baryons and compare with results obtained from models without
vector mesons.Comment: LaTeX, 9 pages, 3 figures, to be published in Phys. Rev.
Stratigraphy of the Woodbine and Eagle Ford, Waco Area, Texas
In the last twenty years, very little detailed stratigraphy of this area has been published. Meanwhile there have been significant advances in this field: the aims of modern stratigraphic research have been somewhat clarified; much new information pertinent to the stratigraphy of this area has been accumulated from the study of other areas; and a considerable amount of detailed information on the surface and subsurface geology of this area has come to light as a result of detailed outcrop work, extensive drilling of oil tests and water wells, and new techniques of bore-hole logging. The scope of this work is mainly the study of beds located near the Lower-Upper Cretaceous boundary, from the Lower Washita to the base of the Austin chalk. This includes very detailed investigations of the Upper Washita beds and the Woodbine and Eagle Ford groups. The lithologic division and the fossil zonation of these strata are outlined, isopach and boundary maps of the various units presented, and the outcrop is tied into the subsurface. It is hoped that these results throw light on the division, definition, zonation, and stratigraphic behavior of both the Woodbine and the Eagle Ford in this area
Recoil corrections in the hydrogen isoelectronic sequence
A version of the Bethe-Salpeter equation appropriate for calculating recoil
corrections in highly charged hydrogenlike ions is presented. The nucleus is
treated as a scalar particle of charge Z, and the electron treated
relativistically. The known recoil corrections of order are
derived in both this formalism and in NRQED
Recommended from our members
Geology of Bell County, Texas
Accompanied by 1 fold-out. Plate 1 : Geologic map of Bell County, Texas. The University of Texas bulletin ; no. 3016 : April 22, 1930UT Librarie
Recommended from our members
Handbook of Texas Cretaceous fossils
Accompanied by 37 foldout plates : Plates 1-37UT Librarie
The Single Photon Annihilation Contributions to the Positronium Hyperfine Splitting to Order
The single photon annihilation contributions for the positronium ground state
hyperfine splitting are calculated analytically to order using
NRQED. Based on intuitive physical arguments the same result can also be
determined by a trivial calculation using results from existing literature. Our
result completes the hyperfine splitting calculation to order . We
compare the theoretical prediction with the most recent experimental
measurement.Comment: 8 pages, latex, two eps figures include
University of Texas bulletin
Report published in a scientific bulletin, describing the geology and mineral resources that reside in McLennan county
Some Ohio Heteroptera Records
Author Institution: Department of Anatomy, University of Illinois, Chicag
alpha^2 corrections to parapositronium decay: a detailed description
We present details of our recent calculation of alpha^2 corrections to the
parapositronium decay into two photons. These corrections are rather small and
our final result for the parapositronium lifetime agrees well with the most
recent measurement. Implications for orthopositronium decays are briefly
discussed.Comment: 18 pages, late
The "recoil" correction of order to hyperfine splitting of positronium ground state
The "recoil" correction of order to the hyperfine splitting of
positronium ground state was found. The formalism employed is based on the
noncovariant perturbation theory in QED. Equation for two-particle component of
full (many-body) wave function is used, in which effective Hamiltonian depends
on the energy of a system. The effective Hamiltonian is not restricted to the
nonrelativistic region, so there is no need in any regularization. To evaluate
integrals over loop momenta, they are divided into "hard" and "soft" parts,
coming from large and small momenta respectively. Soft contributions were found
analytically, and hard ones are evaluated by numerical integration. Some soft
terms due to the retardation cancel each other. To calculate the "hard"
contributions, a great number of noncovariant graphs is replaced by only a few
covariant ones. The hard contribution was found in two ways. The first way is
to evaluate contributions of separate graphs, using the Coulomb gauge. The
second one is to calculate full hard contribution as a whole using the Feynman
gauge. The final result for the "recoil" correction is 0.381(6) m\al^6 and
agrees with those of previous papers. Diagram-to-diagram comparison with the
revised results of Adkins&Sapirstein was done. All the results agree, so the
"recoil" correction is now firmly established. This means a considerable
disagreement with the experimental data.Comment: 28 pages, latex including latex figure
- …