3,245 research outputs found
Using linear gluon polarization inside an unpolarized proton to determine the Higgs spin and parity
Gluons inside an unpolarized proton are in general linearly polarized in the
direction of their transverse momentum, rendering the LHC effectively a
polarized gluon collider. This polarization can be utilized in the
determination of the spin and parity of the newly found Higgs-like boson. We
focus here on the determination of the spin using the azimuthal Collins-Soper
angle distribution.Comment: 6 pages, to appear in the proceedings of the LightCone 2013+
workshop, 20-24 May 2013, Skiathos, Greec
Linearly Polarized Gluons and the Higgs Transverse Momentum Distribution
We study how gluons carrying linear polarization inside an unpolarized hadron
contribute to the transverse momentum distribution of Higgs bosons produced in
hadronic collisions. They modify the distribution produced by unpolarized
gluons in a characteristic way that could be used to determine whether the
Higgs boson is a scalar or a pseudoscalar particle.Comment: 4 pages, 3 figures, final version, published in PR
A goal-oriented requirements modelling language for enterprise architecture
Methods for enterprise architecture, such as TOGAF, acknowledge the importance of requirements engineering in the development of enterprise architectures. Modelling support is needed to specify, document, communicate and reason about goals and requirements. Current modelling techniques for enterprise architecture focus on the products, services, processes and applications of an enterprise. In addition, techniques may be provided to describe structured requirements lists and use cases. Little support is available however for modelling the underlying motivation of enterprise architectures in terms of stakeholder concerns and the high-level goals that address these concerns. This paper describes a language that supports the modelling of this motivation. The definition of the language is based on existing work on high-level goal and requirements modelling and is aligned with an existing standard for enterprise modelling: the ArchiMate language. Furthermore, the paper illustrates how enterprise architecture can benefit from analysis techniques in the requirements domain
Double Sivers effect asymmetries and their impact on transversity measurements at RHIC
We study double transverse spin asymmetries in the Drell-Yan process at
measured transverse momentum of the lepton pair. Contrary to what a collinear
factorization approach would suggest, a nonzero double transverse spin
asymmetry in the laboratory frame a priori does not imply nonzero transversity.
TMD effects, such as the double Sivers effect, in principle form a background.
Using the current knowledge of the relevant TMDs we estimate their contribution
in the laboratory frame for Drell-Yan and W production at RHIC and point out a
cross check asymmetry measurement to bound the TMD contributions. We also
comment on the transverse momentum integrated asymmetries that only receive
power suppressed background contributions.Comment: 12 pages, 11 eps figures, minor changes, matches the published
versio
Hybrid stabilizing control on a real mobile robot
To establish empirical verification of a stabilizing controller for nonholonomic systems, the authors implement a hybrid control concept on a 2-DOF mobile robot. Practical issues of velocity control are also addressed through a velocity controller which transforms the mobile robot to a new system with linear and angular velocity inputs. Experiments in the physical meaning of different controller components provide insights which result in significant improvements in controller performanc
Citation analysis may severely underestimate the impact of clinical research as compared to basic research
Background: Citation analysis has become an important tool for research
performance assessment in the medical sciences. However, different areas of
medical research may have considerably different citation practices, even
within the same medical field. Because of this, it is unclear to what extent
citation-based bibliometric indicators allow for valid comparisons between
research units active in different areas of medical research.
Methodology: A visualization methodology is introduced that reveals
differences in citation practices between medical research areas. The
methodology extracts terms from the titles and abstracts of a large collection
of publications and uses these terms to visualize the structure of a medical
field and to indicate how research areas within this field differ from each
other in their average citation impact.
Results: Visualizations are provided for 32 medical fields, defined based on
journal subject categories in the Web of Science database. The analysis focuses
on three fields. In each of these fields, there turn out to be large
differences in citation practices between research areas. Low-impact research
areas tend to focus on clinical intervention research, while high-impact
research areas are often more oriented on basic and diagnostic research.
Conclusions: Popular bibliometric indicators, such as the h-index and the
impact factor, do not correct for differences in citation practices between
medical fields. These indicators therefore cannot be used to make accurate
between-field comparisons. More sophisticated bibliometric indicators do
correct for field differences but still fail to take into account within-field
heterogeneity in citation practices. As a consequence, the citation impact of
clinical intervention research may be substantially underestimated in
comparison with basic and diagnostic research
A note on a multi-period profit maximizing model for retail supply chain management
In this note we present an efficient exact algorithm to solve the joint pricing and inventory
problem for which Bhattacharjee and Ramesh (2000) proposed two heuristics. Our algorithm
appears to be superior also in terms of computation time. Furthermore, we point out several mistakes in the paper by Bhattacharjee and Ramesh
Four equivalent lot-sizing models
We study the following lot-sizing models that recently appeared in the literature: a lot-sizing model with a
remanufacturing option, a lot-sizing model with production time windows, and a lot-sizing model with cumulative
capacities. We show the equivalence of these models with a classical model: the lot-sizing model with inventory bounds
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