9,740 research outputs found
Unravelling strange quarks in nucleon structure
We present a discourse on the stages of discovery that have led to a deeper
understanding of the role played by strange quarks in the structure of the
nucleon.Comment: 6 pages, 2 figures; prepared for the proceedings of Achievements and
New Directions in Subatomic Physics: Workshop in Honour of Tony Thomas' 60th
Birthda
Nucleon structure in the search for new physics
We report on recent results on nucleon structure that are helping guide the
search for new physics at the precision frontier. Results discussed include the
electroweak elastic form factors, charge symmetry breaking in parton
distributions and the strangeness content of the nucleon.Comment: 6 pages, 2 figures; contribution to the proceedings of "T(r)opical
QCD 2010: Cairns CSSM 2010 Workshop," Cairns, Australia, 26 September - 1
Octobe
Chiral behavior of baryon magnetic moments
The utility of chiral effective field theory, constructed in a manner in
which loop contributions are suppressed as one moves outside the power-counting
regime, is explored for baryon magnetic moments. Opportunities for the study of
significant chiral curvature in valence and full QCD and the nontrivial
behavior of strange- and light-quark contributions to the magnetic moment of
the Lambda baryon are highlighted.Comment: 7 pages, 5 figures; prepared for the proceedings of Achievements and
New Directions in Subatomic Physics: Workshop in Honour of Tony Thomas' 60th
Birthda
Inward foreign direct investment and constitutional change in Scotland
Purpose - To undertake an analysis of the implications of potential Scottish independence for inward foreign direct investment (FDI), multinational enterprise strategies, and the local economy.<p></p>
Design/methodology/approach - Takes a multidisciplinary approach drawing upon literature and evidence in the international business and management, political economy, and economic geography fields to analyze the role and impact of inward FDI in Scotland following possible Scottish independence.<p></p>
Findings - Scotland continues as an attractive location for FDI, with greater diversity than hitherto. While the country’s comparative advantages in immobile natural resources provide some protection from uncertainty, weak embeddedness is a risk factor irrespective of independence. A range of transition costs of independence are identified, which could be high and of indeterminate duration, and some will be sector-specific. There are also new possibilities for tailoring of policies, and potential reindustrialization opportunities in renewable technologies. The foreign investors most vulnerable to political risks and uncertainties are those whose market scope is the rest of the UK (rUK) either as exporters or value chain integrators, in addition to the high political risk industries of energy, banking, and financial services and defence. Scottish subsidiaries’ significance within their parent MNE groups will also be a major factor in determining responses to political risks and uncertainties.<p></p>
Originality/value - Specific focus upon the impact of potential independence on the foreign-owned sector as a major contributor to the Scottish economy.<p></p>
Interactive product browsing and configuration using remote augmented reality sales services
Real-time remote sales assistance is an underdeveloped component of online sales services. Solutions involving web page text chat, telephony and video support prove problematic when seeking to remotely guide customers in their sales processes, especially with configurations of physically complex artefacts. Recently, there has been great interest in the application of virtual worlds and augmented reality to create synthetic environments for remote sales of physical artefacts. However, there is a lack of analysis and development of appropriate software services to support these processes. We extend our previous work with the detailed design of configuration context services to support the management of an interactive sales session using augmented reality. We detail the context and configuration services required, presenting a novel data service streaming configuration information to the vendor for business analytics. We expect that a fully implemented configuration management service, based on our design, will improve the remote sales experience for both customers and vendors alike via analysis of the streamed information
Parental bonding and alexithymia: A meta-analysis
Aim: The primary purpose of this meta-analysis was to explore, clarify and report the strength of the relationship between alexithymia, as measured by the Toronto Alexithymia Scale (TAS-20), and parenting style as measured by the Parental Bonding Instrument (PBI). Methods: Web of Science, PsycInfo, PubMed and ProQuest: Dissertations and Theses searches were undertaken, yielding nine samples with sufficient data to be included in the meta-analysis. Results: Evidence indicated moderate to strong relationships between maternal care and alexithymia, and between maternal care and two of the three TAS-20 alexithymia facets (Difficulties Describing Feelings and Difficulties Identifying Feelings, but not Externally Oriented Thinking). Moderate relationships were observed for both maternal- and paternal-overprotection and alexithymia respectively, and for overprotection (both maternal and paternal) and Difficulties Describing Feelings. Conclusion: This study is the first meta-analysis of the relationship between parenting styles and alexithymia, and findings confirm an especially strong association between maternal care and key elements of alexithymia. This review highlights the issues that still remain to be addressed in exploring the link between parenting style and alexithymia
Dark matter, the CMSSM and lattice QCD
Recent lattice measurements have given accurate estimates of the light and
strange quark condensates in the proton. We use these new results to
significantly improve the dark matter predictions in a set of benchmark models
that represent different scenarios in the constrained minimal supersymmetric
standard model (CMSSM). Because the predicted cross sections are at least an
order of magnitude smaller than previously suggested, our results have
significant consequences for dark matter searches.Comment: 4 pages, 4 figure
Quantum Transport and Integrability of the Anderson Model for a Quantum Dot with Multiple Leads
We show that an Anderson Hamiltonian describing a quantum dot connected to
multiple leads is integrable. A general expression for the non-linear
conductance is obtained by combining the Bethe ansatz exact solution with
Landauer-B\"uttiker theory. In the Kondo regime, a closed form expression is
given for the matrix conductance at zero temperature and when all the leads are
close to the symmetric point. A bias-induced splitting of the Kondo resonance
is possible for three or more leads. Specifically, for leads, with each at
a different chemical potential, there can be Kondo peaks in the
conductance.Comment: 5 pages, 2 figure
Iron line profiles including emission from within the innermost stable orbit of a black hole accretion disc
Reynolds & Begelman (1997) have recently proposed a model in which the broad
and extremely redshifted iron line seen during a deep minimum of the light
curve of the Seyfert 1 galaxy MCG-6-30-15 originates from matter spiralling
into a Schwarzschild black hole, contrary to previous claims that the black
hole may be spinning rapidly (Iwasawa et al 1996; Dabrowski et al 1997). Here
we calculate in detail the X-ray spectrum produced by their model using the
full reflected continuum emission, including absorption features. This
calculation takes into account the doppler and relativistic effects. For the
range of parameters we consider, we find that the spectrum should show a large
photoelectric absorption edge of iron, which is not seen in the data. The
absorption edge is a consequence of the line emitting matter within the
innermost stable orbit being highly ionized, and is largely independent of the
parameters chosen for their model. If we restrict our attention to the 3-10 keV
band we may effectively remove this absorption edge by fitting a steeper power
law, but this results in a significant underprediction of the 0.4-0.5 keV flux.
We conclude that the data on MCG-6-30-15 are more consistent with the Kerr than
the Schwarzschild model.Comment: 5 pages with 5 postscript figures. Accepted for publication in MNRA
Scattering processes and resonances from lattice QCD
The vast majority of hadrons observed in nature are not stable under the
strong interaction, rather they are resonances whose existence is deduced from
enhancements in the energy dependence of scattering amplitudes. The study of
hadron resonances offers a window into the workings of quantum chromodynamics
(QCD) in the low-energy non-perturbative region, and in addition, many probes
of the limits of the electroweak sector of the Standard Model consider
processes which feature hadron resonances. From a theoretical standpoint, this
is a challenging field: the same dynamics that binds quarks and gluons into
hadron resonances also controls their decay into lighter hadrons, so a complete
approach to QCD is required. Presently, lattice QCD is the only available tool
that provides the required non-perturbative evaluation of hadron observables.
In this article, we review progress in the study of few-hadron reactions in
which resonances and bound-states appear using lattice QCD techniques. We
describe the leading approach which takes advantage of the periodic finite
spatial volume used in lattice QCD calculations to extract scattering
amplitudes from the discrete spectrum of QCD eigenstates in a box. We explain
how from explicit lattice QCD calculations, one can rigorously garner
information about a variety of resonance properties, including their masses,
widths, decay couplings, and form factors. The challenges which currently limit
the field are discussed along with the steps being taken to resolve them
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