Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Nuclear Schiff moment in nuclei with soft octupole and quadrupole vibrations  [PDF]
N. Auerbach,V. F. Dmitriev,V. V. Flambaum,A. Lisetskiy,R. A. Sen'kov,V. G. Zelevinsky
Physics , 2006, DOI: 10.1103/PhysRevC.74.025502
Abstract: Nuclear forces violating parity and time reversal invariance (${\cal P},{\cal T}$-odd) produce ${\cal P},{\cal T}$-odd nuclear moments, for example, the nuclear Schiff moment. In turn, this moment can induce the electric dipole moment in the atom. The nuclear Schiff moment is predicted to be enhanced in nuclei with static quadrupole and octupole deformation. The analogous suggestion of the enhanced contribution to the Schiff moment from the soft collective quadrupole and octupole vibrations in spherical nuclei is tested in this article in the framework of the quasiparticle random phase approximation with separable quadrupole and octupole forces applied to the odd $^{217-221}$Ra and $^{217-221}$Rn isotopes. We confirm the existence of the enhancement effect due to the soft modes. However, in the standard approximation the enhancement is strongly reduced by a small weight of the corresponding "particle + phonon" component in a complicated wave function of a soft nucleus. The perspectives of a better description of the structure of heavy soft nuclei are discussed.
Moment of Inertia and Quadrupole Response Function of a Trapped Superfluid  [PDF]
Francesca Zambelli,Sandro Stringari
Physics , 2000, DOI: 10.1103/PhysRevA.63.033602
Abstract: We derive an explicit relationship between the moment of inertia and the quadrupole response function of an interacting gas confined in a harmonic trap. The relationship holds for both Bose and Fermi systems and is well suited to reveal the effects of irrotationality of the superfluid motion. Recent experimental results on the scissors mode are used to extract the value of the moment of inertia of a trapped Bose gas and to point out the deviations from the rigid value due to superfluidity.
The quadrupole moment of slowly rotating fluid balls  [PDF]
Michael Bradley,Gyula Fodor
Physics , 2008, DOI: 10.1103/PhysRevD.79.044018
Abstract: In this paper we use the second order formalism of Hartle to study slowly and rigidly rotating stars with focus on the quadrupole moment of the object. The second order field equations for the interior fluid are solved numerically for different classes of possible equations of state and these solutions are then matched to a vacuum solution that includes the general asymptotically flat axisymmetric metric to second order, using the Darmois-Israel procedure. For these solutions we find that the quadrupole moment differs from that of the Kerr metric, as has also been found for some equations of state in other studies. Further we consider the post-Minkowskian limit analytically. In the paper we also illustrate how the relativistic multipole moments can be calculated from a complex gravitational potential.
Role on Moment of Inertia and Vortex Dynamics for a Thin Rotating Plate  [PDF]
Yoshihiro Kubota, Osamu Mochizuki
World Journal of Mechanics (WJM) , 2013, DOI: 10.4236/wjm.2013.36028

In this study, we focused on the lift generation with a thin rotating plate. The objective of this study is to understand the appropriate shape and the role of vortex for rotating thin plate. We determined the shape of the plate through free-flight tests of paper strips and investigated the aerodynamic characteristics of the rotating plate with the selected shape. The rectangular plate with an aspect ratio 7 was relevant from moment of inertia and bending stress. An endplate on a wing tip increased the stability on the lateral vortex structure behind the rotating plate. Velocity field measurement by Particle Image Velocimetry (PIV) showed that the lift force was generated twice in a rotating cycle.

Observation of a quenched moment of inertia in a rotating strongly interacting Fermi gas  [PDF]
Bason Clancy,Le Luo,John E. Thomas
Physics , 2007, DOI: 10.1103/PhysRevLett.99.140401
Abstract: We make a model-independent measurement of the moment of inertia of a rotating, expanding strongly-interacting Fermi gas. Quenching of the moment of inertia is observed for energies both below and above the superfluid transition. This shows that a strongly interacting Fermi gas with angular momentum can support irrotational flow in both the superfluid and collisional normal fluid regimes.
Metric of a Slow Rotating Body with Quadrupole Moment from the Erez-Rosen Metric  [PDF]
Francisco Frutos-Alfaro, Edwin Retana-Montenegro, Iván Cordero-García, Javier Bonatti-González
International Journal of Astronomy and Astrophysics (IJAA) , 2013, DOI: 10.4236/ijaa.2013.34051

A metric representing a slowly rotating object with quadrupole moment is obtained using a perturbation method to include rotation into the weak limit of the Erez-Rosen metric. This metric is intended to tackle relativistic astrometry and gravitational lensing problems in which a quadrupole moment has to be taken into account.

Effects of surface vibrations on quadrupole response of nuclei  [PDF]
V. I. Abrosimov,A. Dellafiore,F. Matera
Physics , 2002, DOI: 10.1016/S0375-9474(03)00611-0
Abstract: The effect of quadrupole-type surface vibrations on the quadrupole response function of heavy nuclei is studied by using a model based on the solution of the linearized Vlasov equation with moving-surface boundary conditions. By using a separable approximation for the residual interaction, an analytical expression is obtained for the moving-surface response function. Comparison of the fixed- and moving-surface strength functions shows that surface vibrations are essential in order to achieve a unified description of the two characteristic features of the quadrupole response: the giant resonance and the low-lying states. Calculations performed by setting the surface tension equal to zero shows that the low-lying strength is strongly affected by the surface tension.
Pairing in hot rotating nuclei  [PDF]
N. Quang Hung,N. Dinh Dang
Physics , 2008, DOI: 10.1103/PhysRevC.78.064315
Abstract: Nuclear pairing properties are studied within an approach that includes the quasiparticle-number fluctuation (QNF) and coupling to the quasiparticle-pair vibrations at finite temperature and angular momentum. The formalism is developed to describe non-collective rotations about the symmetry axis. The numerical calculations are performed within a doubly-folded equidistant multilevel model as well as several realistic nuclei. The results obtained for the pairing gap, total energy and heat capacity show that the QNF smoothes out the sharp SN phase transition and leads to the appearance of a thermally assisted pairing gap in rotating nuclei at finite temperature. The corrections due to the dynamic coupling to SCQRPA vibrations and particle-number projection are analyzed. The effect of backbending of the momentum of inertia as a function of squared angular velocity is also discussed.
Quadrupole correlations and inertial properties of rotating nuclei  [PDF]
D. Almehed,F. D?nau,R. G. Nazmitdinov
Physics , 2003, DOI: 10.1088/0954-3899/29/9/314
Abstract: The contribution of quantum shape fluctuations to inertial properties of rotating nuclei has been analyzed for QQ-nuclear interaction using the random phase approximation (RPA). The different recipes to treat the cranking mean field plus RPA problem are considered. The effects of the dN=2 quadrupole matrix elements and the role of the volume conservation condition are discussed.
The role of pairing correlations for the description of $β$ vibrations at superdeformed shapes  [PDF]
Piotr Magierski,Ramon Wyss
Physics , 1999,
Abstract: In this paper we analyze the possibility of the appearance of quadrupole vibrational states in superdeformed nuclei from the $A\approx 150$ region. We discuss the role of pairing correlations for a proper description of quadrupole vibrations, especially of the $\beta$ type.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.