The newly observed open-charm states in quark model

Comparing the measured properties of the newly observed open-charm states D(2550), D(2600), D(2750), D(2760), D_{s1}(2710), D_{sJ}(2860), and D_{sJ}(3040) with our predicted spectroscopy and strong decays in a constituent quark model, we find that: (1) the D(2\,^1S_0) assignment to D(2550) remains open for its too broad width determined by experiment; (2) the D(2600) and $D_{s1}(2710)$ can be identified as the 2\,^3S_1-1\,^3D_1 mixtures; (3) if the D(2760) and D(2750) are indeed the same resonance, they would be the D(1\,^3D_3); otherwise, they could be assigned as the D(1\,^3D_3) and $D^\prime_2(1D)$, respectively; (4) the $D_{sJ}(2860)$ could be either the $D_{s1}(2710)$'s partner or the D_s(1\,^3D_3); and (5) both the $D_{s1}(2P)$ and $D^\prime_{s1}(2P)$ interpretations for the $D_{sJ}(3040)$ seem likely. The $E1$ and $M1$ radiative decays of these sates are also studied. Further experimental efforts are needed to test the present quarkonium assignments for these new open-charm states.Comment: 26 pages,7 figures, journal versio

A framework for evaluating automatic image annotation algorithms

Several Automatic Image Annotation (AIA) algorithms have been introduced recently, which have been found to outperform previous models. However, each one of them has been evaluated using either different descriptors, collections or parts of collections, or "easy" settings. This fact renders their results non-comparable, while we show that collection-specific properties are responsible for the high reported performance measures, and not the actual models. In this paper we introduce a framework for the evaluation of image annotation models, which we use to evaluate two state-of-the-art AIA algorithms. Our findings reveal that a simple Support Vector Machine (SVM) approach using Global MPEG-7 Features outperforms state-of-the-art AIA models across several collection settings. It seems that these models heavily depend on the set of features and the data used, while it is easy to exploit collection-specific properties, such as tag popularity especially in the commonly used Corel 5K dataset and still achieve good performance

Supersymmetric Models with Higher Dimensional Operators

In 4D renormalisable theories, integrating out massive states generates in the low energy effective action higher dimensional operators (derivative or otherwise). Using a superfield language it is shown that a 4D N=1 supersymmetric theory with higher derivative operators in either the Kahler or the superpotential part of the Lagrangian and with an otherwise arbitrary superpotential, is equivalent to a 4D N=1 theory of second order (i.e. without higher derivatives) with additional superfields and renormalised interactions. We provide examples where a free theory with trivial supersymmetry breaking provided by a linear superpotential becomes, in the presence of higher derivatives terms and in the second order version, a non-trivial interactive one with spontaneous supersymmetry breaking. The couplings of the equivalent theory acquire a threshold correction through their dependence on the scale of the higher dimensional operator(s). The scalar potential in the second order theory is not necessarily positive definite, and one can in principle have a vanishing potential with broken supersymmetry. We provide an application to MSSM and argue that at tree-level and for a mass scale associated to a higher derivative term in the TeV range, the Higgs mass can be lifted above the current experimental limits.Comment: 36 pages; some clarifications and references adde

Naval Ship Maintenance: An Analysis of the Dutch Shipbuilding Industry Using the Knowledge Value Added, Systems Dynamics, and Integrated Risk Management Methodologies

Sponsored Report (for Acquisition Research Program)Initiatives to reduce the cost of ship maintenance have not yet realized the normal cost-reduction learning curve improvements. One explanation is the lack of recommended technologies. Damen, a Dutch shipbuilding and service firm, has incorporated similar technologies and is developing others to improve its operations. The research team collected data on Dutch ship maintenance operations and used them to build three types of computer simulation models of ship maintenance and technology adoption. The results were analyzed and compared with previously developed modeling results of U.S. Navy ship maintenance and technology adoption. Adopting 3D PDF alone improves ROI significantly more than adopting a logistics package alone and adding both technologies improves ROI more than adding either technology alone. Adoption of the technologies would provide cost benefits far in excess of not using the technologies and there were marginal benefits in sequentially implementing the technologies over immediately implementing them. There are a number of issues in comparing the results with previous research but the potential benefits of using the technologies are very high in both cases. Implications for acquisition practice include the need for careful analysis and selection from among a variety of available information technologies and the recommendation for a phased development and implementation approach to manage uncertainty.Acquisition Research Progra

Continuum-particle hybrid coupling for mass, momentum and energy transfers in unsteady fluid flow

The aim of hybrid methods in simulations is to communicate regions with disparate time and length scales. Here, a fluid described at the atomistic level within an inner region P is coupled to an outer region C described by continuum fluid dynamics. The matching of both descriptions of matter is made across an overlapping region and, in general, consists of a two-way coupling scheme (C->P and P->C) which conveys mass, momentum and energy fluxes. The contribution of the hybrid scheme hereby presented is two-fold: first it treats unsteady flows and, more importantly, it handles energy exchange between both C and P regions. The implementation of the C->P coupling is tested here using steady and unsteady flows with different rates of mass, momentum and energy exchange. In particular, relaxing flows described by linear hydrodynamics (transversal and longitudinal waves) are most enlightening as they comprise the whole set of hydrodynamic modes. Applying the hybrid coupling scheme after the onset of an initial perturbation, the cell-averaged Fourier components of the flow variables in the P region (velocity, density, internal energy, temperature and pressure) evolve in excellent agreement with the hydrodynamic trends. It is also shown that the scheme preserves the correct rate of entropy production. We discuss some general requirements on the coarse-grained length and time scales arising from both the characteristic microscopic and hydrodynamic scales.Comment: LaTex, 12 pages, 9 figure

Contactless charge carrier mobility measurement in organic field-effect transistors

With the increasing performance of organic semiconductors, contact resistances become an almost fundamental problem, obstructing the accurate measurement of charge carrier mobilities. Here, a generally applicable method is presented to determine the true charge carrier mobility in an organic field-effect transistor (OFET). The method uses two additional finger-shaped gates that capacitively generate and probe an alternating current in the OFET channel. The time lag between drive and probe can directly be related to the mobility, as is shown experimentally and numerically. As the scheme does not require the injection or uptake of charges it is fundamentally insensitive to contact resistances. Particularly for ambipolar materials the true mobilities are found to be substantially larger than determined by conventional (direct current) schemes

Full Stark control of polariton states on a spin-orbit hypersphere

The orbital angular momentum and the polarization of light are physical quantities widely investigated for classical and quantum information processing. In this work we propose to take advantage of strong light-matter coupling, circular-symmetric confinement, and transverse-electric transverse-magnetic splitting to exploit states where these two degrees of freedom are combined. To this end we develop a model based on a spin-orbit Poincaré hypersphere. Then we consider the example of semiconductor polariton systems and demonstrate full ultrafast Stark control of spin-orbit states. Moreover, by controlling states on three different spin-orbit spheres and switching from one sphere to another we demonstrate the control of different logic bits within one single physical system