121,026 research outputs found

    Narrative in design development

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    This paper describes the value of narrative used with ideation tools in aiding the rapid production of product concepts and designs for masters students of graphics, fine art, product and industrial design. The ideation tools used alongside narrative included elements of divergent and convergent thinking in combination with reverse engineering and functional analysis, and practical prototyping using a range of readily adapted artefacts. Narrative was introduced and used by the students in order to ensure the development of a context and purpose for the product, artefact or system developed or proposed and to stimulate original product concepts, ideas and thinking. The concept of narrative is familiar in design. Here however the concept was reinforced using structures associated with fictional narrative. Reverse engineering exploring the deconstruction and identification of function for each component in a product was used to aid students ensure practicality in their idea implementation. This paper describes positive experiences resulting from this activity, with a particular focus on the value of narrative in developing robust concepts. The use of physical prototyping provided tangible and instant feedback for divergent and convergent phases of idea development

    Breakdown of QCD Factorization for P-Wave Quarkonium Production at Low Transverse Momentum

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    Quarkonium production at low transverse momentum in hadron collisions can be used to extract Transverse-Momentum-Dependent(TMD) gluon distribution functions, if TMD factorization holds there. We show that TMD factorization for the case of P-wave quarkonium with JPC=0++,2++J^{PC}=0^{++}, 2^{++} holds at one-loop level, but is violated beyond one-loop level. TMD factorization for other P-wave quarkonium is also violated already at one-loop.Comment: Published version in Physics Letters B (2014), pp. 103-10

    Transverse Momentum Dependent Factorization for Quarkonium Production at Low Transverse Momentum

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    Quarkonium production in hadron collisions at low transverse momentum q⊥≪Mq_\perp \ll M with MM as the quarkonium mass can be used for probing transverse momentum dependent (TMD) gluon distributions. For this purpose, one needs to establish the TMD factorization for the process. We examine the factorization at the one-loop level for the production of ηc\eta_c or ηb\eta_b. The perturbative coefficient in the factorization is determined at one-loop accuracy. Comparing the factorization derived at tree level and that beyond the tree level, a soft factor is, in general, needed to completely cancel soft divergences. We have also discussed possible complications of TMD factorization of p-wave quarkonium production.Comment: Title changed in the journal, published versio

    New parametrization for the nuclear covariant energy density functional with point-coupling interaction

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    A new parametrization PC-PK1 for the nuclear covariant energy density functional with nonlinear point-coupling interaction is proposed by fitting to observables for 60 selected spherical nuclei, including the binding energies, charge radii and empirical pairing gaps. The success of PC-PK1 is illustrated in its description for infinite nuclear matter and finite nuclei including the ground-state and low-lying excited states. Particularly, PC-PK1 improves the description for isospin dependence of binding energy along either the isotopic or the isotonic chains, which makes it more reliable for application in exotic nuclei. The predictive power of PC-PK1 is also illustrated for the nuclear low-lying excitation states in a five-dimensional collective Hamiltonian in which the parameters are determined by constrained calculations for triaxial shapes.Comment: 32 pages, 12 figures, 4 tables, accepted by Phys. Rev.

    On the kinematic signature of a central Galactic bar in observed star samples

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    A quasi self-consistent model for a barred structure in the central regions of our Galaxy is used to calculate the signature of such a triaxial structure on the kinematical properties of star samples. We argue that, due to the presence of a velocity dispersion, such effects are much harder to detect in the stellar component than in the gas. It might be almost impossible to detect stellar kinematical evidence for a bar using only l-v diagrams, if there is no a priori knowledge of the potential. Therefore, we propose some test parameters that can easily be applied to observed star samples, and that also incorporate distances or proper motions. We discus the diagnostic power of these tests as a function of the sample size and the bar strength. We conclude that about 1000 stars would be necessary to diagnose triaxiality with some statistical confidence.Comment: 9 pages + 8 PS figures, uses aas2pp4.sty. Accepted by Ap

    Antimagnetic Rotation Band in Nuclei: A Microscopic Description

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    Covariant density functional theory and the tilted axis cranking method are used to investigate antimagnetic rotation (AMR) in nuclei for the first time in a fully self-consistent and microscopic way. The experimental spectrum as well as the B(E2) values of the recently observed AMR band in 105Cd are reproduced very well. This gives a further strong hint that AMR is realized in specific bands in nuclei.Comment: 10 pages, 4 figure
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