2,620 research outputs found

    DsJ(2860)D_{sJ}(2860) and DsJ(2715)D_{sJ}(2715)

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    Recently Babar Collaboration reported a new csˉc\bar{s} state DsJ(2860)D_{sJ}(2860) and Belle Collaboration observed DsJ(2715)D_{sJ}(2715). We investigate the strong decays of the excited csˉc\bar{s} states using the 3P0^{3}P_{0} model. After comparing the theoretical decay widths and decay patterns with the available experimental data, we tend to conclude: (1) DsJ(2715)D_{sJ}(2715) is probably the 1(13D1)1^{-}(1^{3}D_{1}) csˉc\bar{s} state although the 1(23S1)1^{-}(2^{3}S_{1}) assignment is not completely excluded; (2) DsJ(2860)D_{sJ}(2860) seems unlikely to be the 1(23S1)1^{-}(2^{3}S_{1}) and 1(13D1)1^{-}(1^{3}D_{1}) candidate; (3) DsJ(2860)D_{sJ}(2860) as either a 0+(23P0)0^{+}(2^{3}P_{0}) or 3(13D3)3^{-}(1^{3}D_{3}) csˉc\bar{s} state is consistent with the experimental data; (4) experimental search of DsJ(2860)D_{sJ}(2860) in the channels DsηD_s\eta, DKDK^{*}, DKD^{*}K and DsηD_{s}^{*}\eta will be crucial to distinguish the above two possibilities.Comment: 18 pages, 7 figures, 2 tables. Some discussions added. The final version to appear at EPJ

    Measurement of the elastic tensor of SmScO3 and NdSc03 using resonant ultrasound spectroscopy with ab initio calculations

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    The complete elastic tensors of SmScO3 and NdScO3 were measured using resonant ultrasound spectroscopy (RUS) in combination with ab-initio calculations. Measurement of the elastic tensor of these recently synthesized single crystal RE scandates is essential for understanding dynamic lattice applications including phonon confinement, strain induced thin film growth and superlattice construction. On average, the experimental elastic constants differed by less than 5% of the theoretical values, further validating the accuracy of modern ab-initio calculations as a means of estimating the initial elastic constants used in RUS measurements

    Hybrid Meson Decay Phenomenology

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    The phenomenology of a newly developed model of hybrid meson decay is developed. The decay mechanism is based on the heavy quark expansion of QCD and the strong coupling flux tube picture of nonperturbative glue. A comprehensive list of partial decay widths of a wide variety of light, ssˉs\bar s, ccˉc\bar c, and bbˉb \bar b hybrid mesons is presented. Results which appear approximately universal are highlighted along with those which distinguish different hybrid decay models. Finally, we examine several interesting hybrid candidates in detail.Comment: 37 pages, 2 figures, 6 tables, Revte

    AtollGame: A companion modelling experience in the Pacific

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    Multi-Agent Systems (MAS) have been developed to study the interaction between societies and the environment. Here we use MAS in conjunction with a Companion Modelling (ComMod) approach to develop a Negotiation Support System for groundwater management in Tarawa, Republic of Kiribati. In agreement with the complex and dynamic nature of the processes under study, the ComMod approach requires a permanent and iterative confrontation between theories and field circumstances. Therefore, it is based on repetitive back and forth steps between the model and the field situation. The methodology applied in Tarawa relies on 3 successive stages. First, a Global Targeted Appraisal focus on social group leaders in order to collect different standpoints and their articulated mental models. These collective models are partly validated through Individual Activities Surveys focusing behavioural patterns of individual islanders. Then, these models are merged into a single conceptual model that is further simplified in order to create a role-playing game. This game is played during iterative sessions, generating innovative rules and scenarios. Finally, when the rules become too complex, a computer based version of the game replaces the board version. Stakeholders can explore the possible futures of freshwater management in Tarawa and eventually agree on an equitable collective solution

    Configuration mixing in 188^{188}Pb : band structure and electromagnetic properties

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    In the present paper, we carry out a detailed analysis of the presence and mixing of various families of collective bands in 188^{188}Pb. Making use of the interacting boson model, we construct a particular intermediate basis that can be associated with the unperturbed bands used in more phenomenological studies. We use the E2 decay to construct a set of collective bands and discuss in detail the B(E2)-values. We also perform an analysis of these theoretical results (Q, B(E2)) to deduce an intrinsic quadrupole moment and the associated quadrupole deformation parameter, using an axially deformed rotor model.Comment: submitted to pr

    Probing Interstellar Dust with Infrared Echoes from the Cas A Supernova

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    We present the analysis of an IRS 5-38 {\mu}m spectrum and MIPS photometric measurements of an infrared echo near the Cassiopeia A supernova remnant observed with the Spitzer Space Telescope. We have modeled the recorded echo accounting for PAHs, quantum-heated carbon and silicate grains, as well as thermal carbon and silicate particles. Using the fact that optical light echo spectroscopy has established that Cas A originated from a type IIb supernova explosion showing an optical spectrum remarkably similar to the prototypical type IIb SN 1993J, we use the latter to construct template data input for our simulations. We are then able to reproduce the recorded infrared echo spectrum by combining the emission of dust heated by the UV burst produced at the shock breakout after the core-collapse and dust heated by optical light emitted near the visual maximum of the supernova light curve, where the UV burst and optical light curve characteristics are based on SN 1993J. We find a mean density of \sim680 H cm^{-3} for the echo region, with a size of a few light years across. We also find evidence of dust processing in the form of a lack of small PAHs with less than \sim300 carbon atoms, consistent with a scenario of PAHs destruction by the UV burst via photodissociation at the estimated distance of the echo region from Cas A. Furthermore, our simulations suggest that the weak 11 {\mu}m features of our recorded infrared echo spectrum are consistent with a strong dehydrogenated state of the PAHs. This exploratory study highlights the potential of investigating dust processing in the interstellar medium through infrared echoes.Comment: 16 pages, 14 figures, accepted for publication in the Astrophysical Journa
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