15,016 research outputs found
Creutz Ratios From Color-Truncated Lattice Configurations
We investigate whether information about Creutz ratios is encoded,
separately, in each gluon color component of numerically generated lattice
configurations. Working in SU(2) lattice gauge theory in Landau gauge, we set
two of the three gluon color components to zero, and compensate for the loss of
two-thirds of the fluctuation by simply rescaling the remaining component by a
factor of . Creutz ratios are then computed with this "abelianized"
configuration. We find that the Creutz ratios of loops constructed from
abelianized links converge to the usual Creutz ratios in the scaling regime.Comment: 5 pages, plain LaTeX, one figur
Unimolecular reaction rates in solution and in the isolated molecule: Comparison of diphenyl butadiene nonradiative decay in solutions and supersonic jets
The recent study of diphenyl butadiene (DPB) in supersonic jets and in solution by Shepanski et al.(1) and by Courtney and Felming(2), respectively, provides an opportunity to compare the isomerization rates measured in the isolated molecule (jet) with those measured at very low viscosity in solution. These comparisons should shed light on the vibrational energy flows between “optical” and “reactive” modes in the isolated molecule and on the connection between activated, friction dependent, models of barrier crossing in solution,(3-5) and statistical RRK (or RRKM) theories of gas phase unimolecular reactions(6)
Exclusive Radiative Decays of Upsilon in SCET
We study exclusive radiative decays of the using soft-collinear
effective theory and non-relativistic QCD. In contrast to inclusive radiative
decays at the endpoint we find that color-octet contributions are power
suppressed in exclusive decays, and can safely be neglected, greatly
simplifying the analysis. We determine the complete set of Lorentz structures
that can appear in the SCET Wilson coefficients and match onto them using
results from a previous calculation. We run these coefficients from the scale
\mups to the scale , thereby summing large
logarithms. Finally we use our results to predict the ratio of branching
fractions , , and the partial rate for .Comment: 17 pages, 2 figures. Updated to reflect published versio
A Mechanism for Ferrimagnetism and Incommensurability in One-Dimensional Systems
A mechanism for ferrimagnetism in
(1+1)-dimensions is discussed. The ferrimagnetism is cased by interactions
described by operators with non-zero conformal spin. Such interactions appear
in such problems as the problem of tunneling between Luttinger liquids and the
problem of frustrated spin ladder. I present exact solutions for a
representative class of models containing such interactions together with a
simple mean field analysis. It is shown that the interactions (i) dynamically
generate static oscillations with a wave vector dependent on the coupling
constant, (ii) give rise to a finite magnetic moment at accompanied by
the soft mode with a non-relativistic ({\it ferromagnetic}) dispersion , (iii) generate massive (roton) modes.Comment: replaced by the extended version, references adde
Deviations and Mean Reversion to Purchasing Power in the Asian Currency Crisis of 1997
We analyse the process of mean reversion towards purchasing power parity (PPP) for a sample of Asian countries around the 1997 crisis. It is found that appreciation relative to PPP is evident prior to the 1997 crash period. Correction occurs from 1997 onwards, a period marked by extreme movements in exchange rates with both appreciation and depreciation relative to the PPP rate over relatively short periods. The key result of this paper is that although reversion towards PPP is apparent for mean, though not statistically significant, it is clear that there is a substantial, statistically significant change in variance from 1997 onwards. This result has implications both for economic modelling of crash periods and for appropriate choice of statistical tests
Factorization of e+e- Event Shape Distributions with Hadronic Final States in Soft Collinear Effective Theory
We present a new analysis of two-jet event shape distributions in soft
collinear effective theory. Extending previous results, we observe that a large
class of such distributions can be expressed in terms of vacuum matrix elements
of operators in the effective theory. We match these matrix elements to the
full theory in the two-jet limit without assuming factorization of the complete
set of hadronic final states into independent sums over partonic collinear and
soft states. We also briefly discuss the relationship of this approach to
diagrammatic factorization in the full theory.Comment: 21 pages. Journal version. Defined an explicit thrust axis operator;
clarified meaning of a delta function operato
Purchasing Power Parity and Emerging South East Asian Nations
This paper provides a test of purchasing power parity (PPP) as an explanation for longterm foreign exchange rate movements. It essentially extends the analysis of Cheung and Lai (1993) to the South East Asian nations, Indonesia, the Philippines, Malaysia, South Korea, and Thailand. Consistent with Cheung and Lai, we impose symmetry and proportionality restrictions flowing from the absolute form of purchasing power parity (PPP) as well as applying the less restrictive Johansen test of PPP to data drawn from the period 1972 through 1997. The tests are also run for sub-periods with similar results. Symmetry and proportionality restrictions find little support in the unit root tests though the Johansen tests suggest that the foreign exchange rate and inflation rates are linked in a long run sense. Error correction models are then estimated on the basis of the assumption that the USA inflation rate is exogenous with respect to the selected emerging South East Asian nations. The error correction models vary considerably across the countries though one consistent result is the negative relation between the foreign exchange rate and the error correction parameter and the generally positive relation between the local CPI and the error correction parameter. The impact of the USA CPI on the countries varies considerably, ranging from no impact in the case of Indonesia through to a statistically significant impact on both the foreign exchange rate and local CPI for South Korea
Impacts of unconventional gas development on rural community decline
AbstractThis paper looks at the impact of a new extractive industry, namely unconventional natural gas, on rural decline. Rural decline is defined as comprising loss of rural youth, reduced human capital and increasing rural poverty. Since the start of the current century, the unconventional natural gas industry has been expanding around the world, often in close proximity to pre-existing agricultural communities. The social impacts of this new industry represent a growing area of interest in rural studies. We contribute to this new research area through a case study of coal seam gas (CSG) development in Queensland, Australia, comparing regions where gas development occurred between 2001 and 2011 against a control group of similar regions without gas development. The study eliminated the influence of non-resident workforces by analysing census data based on place of usual residence as well as place of enumeration. A key finding of the study is that regions with CSG development have experienced a growing youth share of the population and, of particular note, a growing female youth share of the population. CSG regions had a higher proportion of youth with university degrees and advanced technical training compared to other rural regions. Poverty reduction was also observed in some specific CSG regions. The extensive spatial footprint of unconventional gas and increased female rural youth populations indicate a diversion from traditional boomtown social impacts observed in previous energy booms. Taken together, the results show signs of mitigating and reversing rural community decline
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