2,798 research outputs found
The Anomalous Magnetic Moments of the Electron and the Muon - Improved QED Predictions Using Pade Approximants
We use Pade Approximants to obtain improved predictions for the anomalous
magnetic moments of the electron and the muon. These are needed because of the
very precise experimental values presently obtained for the electron, and soon
to be obtained at BNL for the muon. The Pade prediction for the QED
contribution to the anomalous magnetic moment of the muon differs significantly
from the naive perturbative prediction.Comment: 8 pages (LateX); SLAC-PUB-6670, CERN-TH-7451/94, TAUP-2201-94,
OSU-RN-393/94. Typo correcte
Reconnaissance study of ground-water levels and withdrawls in the vicinity of DeWitt and Piatt counties
"Prepared for the Mahomet Valley Water Authority.
Matters of Preference: Tracing the Line between Citizens, Democratic States, and International Law
In this Article, we assess the role the aggregation of citizen preferences into the foreign policy choices of a democratic country might play in the legitimization of international law. After addressing some of the theoretical and empirical issues associated with such an approach, we use an anticipated reaction model developed by Michael Bailey to show that even in large democracies there are mechanisms through which citizen preferences can be and are reflected in the policy choices of their representatives.
Incumbents and candidates for office take policy positions in hopes of maximizing their future election chances. Although policymakers each have their own personal policy preferences, those preferences must be balanced against those of the electorate to optimize the prospects for future election. Rational well-informed policymakers anticipate future electoral consequences of public opinion and adjust their present policy positions accordingly. We then discuss the implications of such an approach for the principle of subsidiarity and the participation of states in multilateral institutions, in particular the International Monetary Fund. We argue that there is reason to believe that citizen preferences remain relevant in decisions whether to centralize or decentralize, and in decisions whether a state will support or undermine the mission of international institutions, which must be taken into account as those institutions make their own substantive and procedural choices
A Prediction for the 4-Loop \beta Function
We predict that the four-loop contribution \beta_3 to the QCD \beta function
in the MS-bar prescription is given by
\beta_3\simeq 23,600(900) - 6,400(200) N_f + 350(70) N_f^2 + 1.5 N_f^3, where
N_f is the number of flavours and the coefficient of N_f^3 is an exact result
from large-N_f expansion. In the phenomenologically-interesting case N_f=3, we
estimate \beta_3 = (7.6 \pm 0.1) x 10^3. We discuss our estimates of the errors
in these QCD predictions, basing them on the demonstrated accuracy of our
method in test applications to the O(N) \Phi^4 theory, and on variations in the
details of our estimation method, which goes beyond conventional Pade
approximants by estimating and correcting for subasymptotic deviations from
exact results.Comment: 11 pages, LaTeX, including 2 figures in 3 ps files; requires
epsfig.sty; added comparison with recent exact result
How IT Continuing Education Has Transformed Our Library
Excerpt: Having the skills and knowledge to adequately respond to technology-based information demands has never been more important. When the library at East Tennessee State University was opened in 1999, it was the first new academic building that had been constructed on the campus in a number of years
Calculations of Neutralino-Stau Coannihilation Channels and the Cosmologically Relevant Region of MSSM Parameter Space
Assuming that the lightest supersymmetric particle (LSP) is the lightest
neutralino, we present a detailed exploration of neutralino-stau coannihilation
channels, including analytical expressions and numerical results. We also
include neutralino coannihilations with the selectron and smuon. We evaluate
the implications of coannihilations for the cosmological relic density of the
LSP, which is assumed to be stable, in the constrained minimal supersymmetric
extension of the Standard Model (CMSSM), in which the soft
supersymmetry-breaking parameters are universal at the supergravity GUT scale.
We evaluate the changes due to coannihilations in the region of the MSSM
parameter space that is consistent with the cosmological upper limit on the
relic LSP density. In particular, we find that the upper limit on the mass of
the neutralino is increased from about 200 GeV to about 600 GeV in the CMSSM,
and estimate a qualitatively similar increase for gauginos in the general MSSM.Comment: 38 pages in LaTeX, including 25 encapsulated postscript figures.
Added small clarification in the text, corrected some typos in the appendix.
Figures and conclusions unchange
Corrections to Bino Annihilation II: One-Loop Contribution to
We calculate the one-loop contribution to the bino annihilation rate due to
the process , which vanishes at tree level.Comment: 8 pages in LaTex plus 5 postscript figures (included),
UCSBTH--94--02, UMN--TH--1233/9
Regulation of apical vesicle formation from the trans-Golgi network
Polarized epithelial cells efficiently sort newly-synthesized apical and basolateral proteins into distinct transport carriers that emerge from the trans-Golgi network (TGN), and this sorting may be recapitulated in nonpolarized cells. While the targeting signals of basolaterally-destined proteins are generally cytoplasmically-disposed, apical sorting signals are not typically accessible to the cytosol, and the transport machinery required for segregation and export of apical cargo remain largely unknown. We are interested in identifying the molecular requirements for TGN export of the apical marker influenza hemagglutinin (HA). To identify cytosolic proteins responsible for HA export from the TGN, we developed an in vitro assay to measure this process. We found that HA export does not require the brefeldin A-sensitive GTPase ARF1, but does depend on the GTPase dynamin 2. Furthermore, using biochemical fractionation, we identified the adaptor protein 14-3-3 epsilon as an effector of HA export from the TGN. This work 1) establishes a method to accurately observe anterograde TGN export of an apical cargo, 2) characterizes a requirement for GTP in vesicle formation, and 3) identifies a novel component in trafficking from the TGN. We expand these studies by comparing HA export to the release of basolateral cargo, showing that nonpolarized cells are capable of differentially sorting distinct classes of cargo into discrete vesicles derived from the TGN. Together, these data further our understanding of the regulatory mechanisms underlying apical transmembrane protein export from the TGN
Pade Approximants, Borel Transforms and Renormalons: the Bjorken Sum Rule as a Case Study
We prove that Pade approximants yield increasingly accurate predictions of
higher-order coefficients in QCD perturbation series whose high-order behaviour
is governed by a renormalon. We also prove that this convergence is accelerated
if the perturbative series is Borel transformed. We apply Pade approximants and
Borel transforms to the known perturbative coefficients for the Bjorken sum
rule. The Pade approximants reduce considerably the renormalization-scale
dependence of the perturbative correction to the Bjorken sum rule. We argue
that the known perturbative series is already dominated by an infra-red
renormalon, whose residue we extract and compare with QCD sum-rule estimates of
higher-twist effects. We use the experimental data on the Bjorken sum rule to
extract , including theoretical
errors due to the finite order of available perturbative QCD calculations,
renormalization-scale dependence and higher-twist effects.Comment: 13 pages (latex) + 4 ps figures uuencoded in a self-unpacking fil
Constraints from Inflation and Reheating on Superpartner Masses
Flat directions in the Minimal Supersymmetric Standard Model (MSSM) can
become unstable due to radiative corrections, and the global minimum of the
(zero temperature) potential can lie at large values of the squark and/or
slepton fields. Here we show that, in inflationary models of early cosmology,
the universe is very likely to be in the domain of attraction of this global
minimum at the end of inflation. While the minimum at the origin of field space
is global at sufficiently high temperatures, depending on details of the model,
the universe may be trapped in the non-zero minimum until it becomes the global
minimum at low temperatures. Parameter values leading to this scenario are
therefore ruled out.Comment: 14 pages in LaTeX + 2 postscript figures, uses epsf.sty; revised
version, effect of Yukawa couplings added, figure modified, one figure added,
references altere
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