157,074 research outputs found

    Understanding the different rotational behaviors of 252^{252}No and 254^{254}No

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    Total Routhian surface calculations have been performed to investigate rapidly rotating transfermium nuclei, the heaviest nuclei accessible by detailed spectroscopy experiments. The observed fast alignment in 252^{252}No and slow alignment in 254^{254}No are well reproduced by the calculations incorporating high-order deformations. The different rotational behaviors of 252^{252}No and 254^{254}No can be understood for the first time in terms of β6\beta_6 deformation that decreases the energies of the νj15/2\nu j_{15/2} intruder orbitals below the N=152 gap. Our investigations reveal the importance of high-order deformation in describing not only the multi-quasiparticle states but also the rotational spectra, both providing probes of the single-particle structure concerning the expected doubly-magic superheavy nuclei.Comment: 5 pages, 4 figures, the version accepted for publication in Phys. Rev.

    Localization of Macroscopic Object Induced by the Factorization of Internal Adiabatic Motion

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    To account for the phenomenon of quantum decoherence of a macroscopic object, such as the localization and disappearance of interference, we invoke the adiabatic quantum entanglement between its collective states(such as that of the center-of-mass (C.M)) and its inner states based on our recent investigation. Under the adiabatic limit that motion of C.M dose not excite the transition of inner states, it is shown that the wave function of the macroscopic object can be written as an entangled state with correlation between adiabatic inner states and quasi-classical motion configurations of the C.M. Since the adiabatic inner states are factorized with respect to each parts composing the macroscopic object, this adiabatic separation can induce the quantum decoherence. This observation thus provides us with a possible solution to the Schroedinger cat paradoxComment: Revtex4,23 pages,1figur

    Effects of high order deformation on superheavy high-KK isomers

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    Using, for the first time, configuration-constrained potential-energy-surface calculations with the inclusion of β6\beta_6 deformation, we find remarkable effects of the high order deformation on the high-KK isomers in 254^{254}No, the focus of recent spectroscopy experiments on superheavy nuclei. For shapes with multipolarity six, the isomers are more tightly bound and, microscopically, have enhanced deformed shell gaps at N=152N=152 and Z=100Z=100. The inclusion of β6\beta_6 deformation significantly improves the description of the very heavy high-KK isomers.Comment: 5 pages, 4 figures, 1 table, the version to appear in Phys. Rev.

    Runup and rundown generated by three-dimensional sliding masses

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    To study the waves and runup/rundown generated by a sliding mass, a numerical simulation model, based on the large-eddy-simulation (LES) approach, was developed. The Smagorinsky subgrid scale model was employed to provide turbulence dissipation and the volume of fluid (VOF) method was used to track the free surface and shoreline movements. A numerical algorithm for describing the motion of the sliding mass was also implemented. To validate the numerical model, we conducted a set of large-scale experiments in a wave tank of 104m long, 3.7m wide and 4.6m deep with a plane slope (1:2) located at one end of the tank. A freely sliding wedge with two orientations and a hemisphere were used to represent landslides. Their initial positions ranged from totally aerial to fully submerged, and the slide mass was also varied over a wide range. The slides were instrumented to provide position and velocity time histories. The time-histories of water surface and the runup at a number of locations were measured. Comparisons between the numerical results and experimental data are presented only for wedge shape slides. Very good agreement is shown for the time histories of runup and generated waves. The detailed three-dimensional complex flow patterns, free surface and shoreline deformations are further illustrated by the numerical results. The maximum runup heights are presented as a function of the initial elevation and the specific weight of the slide. The effects of the wave tank width on the maximum runup are also discussed

    A short note on the nested-sweep polarized traces method for the 2D Helmholtz equation

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    We present a variant of the solver in Zepeda-N\'u\~nez and Demanet (2014), for the 2D high-frequency Helmholtz equation in heterogeneous acoustic media. By changing the domain decomposition from a layered to a grid-like partition, this variant yields improved asymptotic online and offline runtimes and a lower memory footprint. The solver has online parallel complexity that scales \emph{sub linearly} as O(NP)\mathcal{O} \left( \frac{N}{P} \right), where NN is the number of volume unknowns, and PP is the number of processors, provided that P=O(N1/5)P = \mathcal{O}(N^{1/5}). The variant in Zepeda-N\'u\~nez and Demanet (2014) only afforded P=O(N1/8)P = \mathcal{O}(N^{1/8}). Algorithmic scalability is a prime requirement for wave simulation in regimes of interest for geophysical imaging.Comment: 5 pages, 5 figure
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