2,107 research outputs found
Construction of gauge invariant effective nucleonic theories: functional approach
Starting from relativistic quantum field theories, describing interacting
nucleons and pions coupled to the dynamical electromagnetic field, the pion
degrees of freedom are eliminated by means of functional integration. Apart
from taking into account some operators perturbatively in , e.g. the vacuum
polarization, this procedure is exact, giving effective theories for nucleons
and photons. The subsequent nonrelativistic reduction yields the corresponding
nonrelativistic quantum field theory. The latter is unique, irrespective of the
precize form of the original nucleon-pion interaction. Nucleonic potentials and
electromagnetic interactions are mutually consistent. Local gauge invariance is
satisfied at any stage of the formal developments.Comment: 15 pages, LaTe
A representative sampling plan for auditing health insurance claims
A stratified sampling plan to audit health insurance claims is offered. The
stratification is by dollar amount of the claim. The plan is representative in
the sense that with high probability for each stratum, the difference in the
average dollar amount of the claim in the sample and the average dollar amount
in the population, is ``small.'' Several notions of ``small'' are presented.
The plan then yields a relatively small total sample size with the property
that the overall average dollar amount in the sample is close to the average
dollar amount in the population. Three different estimators and corresponding
lower confidence bounds for over (under) payments are studied.Comment: Published at http://dx.doi.org/10.1214/074921707000000094 in the IMS
Lecture Notes Monograph Series
(http://www.imstat.org/publications/lecnotes.htm) by the Institute of
Mathematical Statistics (http://www.imstat.org
Analysis of the Low-Energy Theorem for \gamma p \to p \pi^0
The derivation of the `classical' low-energy theorem (LET) for \gamma p
\rightarrow p\pi^0 is re-examined and compared to chiral perturbation theory.
Both results are correct and are not contradictory; they differ because
different expansions of the same quantity are involved. Possible modifications
of the extended partially conserved axial-vector current relation, one of the
starting points in the derivation of the LET, are discussed. An alternate, more
transparent form of the LET is presented.Comment: 5 pages, Revtex, no figures, no table
The electron-nucleon cross section in reactions
We examine commonly used approaches to deal with the scattering of electrons
from a bound nucleon. Several prescriptions are shown to be related by gauge
transformations. Nevertheless, due to current non-conservation, they yield
different results. These differences reflect the size of the uncertainty that
persists in the interpretation of experiments.Comment: 6 pp (10 in preprint form), ReVTeX, (+ 4 figures, uuencoded
Hamiltonian Flow Equations for a Dirac Particle in an External Potential
We derive and solve the Hamiltonian flow equations for a Dirac particle in an
external static potential. The method shows a general procedure for the set up
of continuous unitary transformations to reduce the Hamiltonian to a
quasidiagonal form.Comment: 6 page
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