3,028 research outputs found
Perturbative spectrum of Trapped Weakly Interacting Bosons in Two Dimensions
We study a trapped Bose-Einstein condensate under rotation in the limit of
weak, translational and rotational invariant two-particle interactions. We use
the perturbation-theory approach (the large-N expansion) to calculate the
ground-state energy and the excitation spectrum in the asymptotic limit where
the total number of particles N goes to infinity while keeping the total
angular momentum L finite. Calculating the probabilities of different
configurations of angular momentum in the exact eigenstates gives us a clear
view of the physical content of excitations. We briefly discuss the case of
repulsive contact interaction.Comment: Revtex, 10 pages, 1 table, to appear in Phys. Rev.
Recommended from our members
Overcoming weak intrinsic depolarizing resonances with energy-jump
In the recent polarized proton runs in the AGS, a 5% partial snake was used successfully to overcome the imperfection depolarizing resonances. Polarized proton beam was accelerated up to the required RHIC injection energy of 25 GeV. However, significant amount of polarization was lost at 0+{nu}{sub y}, 12+{nu}{sub y} and 36+{nu}{sub y}, which is believed to be partially due to the coupling resonances. To overcome the coupling resonance, an energy-jump was generated by rapidly changing the beam circumference using the powerful AGS rf system. It clearly demonstrates that the novel energy-jump method can successfully overcome coupling resonances and weak intrinsic resonances
Recommended from our members
Polarized proton experiment in the AGS with a partial snake
In three polarized proton runs at the AGS it was recently shown that the imperfection depolarizing resonances in the AGS can be overcome with a 5% partial snake and the intrinsic depolarizing resonances could be jumped with the pulsed tune-jump quadrupoles even in the presence of the partial snake. For the first time polarized proton beam was accelerated up to the required RHIC injection energy of 25 GeV. No polarization was lost due to the imperfection resonances and the depolarization from most intrinsic resonances was avoided with the tune-jump quadrupoles. However, significant amount of polarization was lost at 0+{nu}{sub y}, 12+{nu}{sub y} and 36+{nu}{sub y}, which is believed to be partially due to coupling resonances. A novel energy-jump method and other new schemes to overcome the coupling and intrinsic resonances are discussed
Continuous Monitoring of Dynamical Systems and Master Equations
We illustrate the equivalence between the non-unitary evolution of an open
quantum system governed by a Markovian master equation and a process of
continuous measurements involving this system. We investigate a system of two
coupled modes, only one of them interacting with external degrees of freedom,
represented, in the first case, by a finite number of harmonic oscillators,
and, in the second, by a sequence of atoms where each one interacts with a
single mode during a limited time. Two distinct regimes appear, one of them
corresponding to a Zeno-like behavior in the limit of large dissipation
On the choice of heavy baryon currents in the relativistic three-quark model
We test the sensitivity of bottom baryon observables with regard to the
choice of the interpolating three-quark currents within the relativistic
three-quark model. We have found that the semileptonic decay rates are clearly
affected by the choice of currents, whereas the asymmetry parameters show only
a very weak dependence on the choice of current.Comment: revtex, 9 page
Proton-Antiproton Annihilation into a Lambda_c-Antilambda_c Pair
The process p-pbar -> Lambda_c-Antilambda_c is investigated within the
handbag approach. It is shown that the dominant dynamical mechanism,
characterized by the partonic subprocess u-ubar -> c-cbar factorizes in the
sense that only the subprocess contains highly virtual partons, a gluon to
lowest order of perturbative QCD, while the hadronic matrix elements embody
only soft scales and can be parameterized in terms of helicity flip and
non-flip generalized parton distributions. Modelling these parton distributions
by overlaps of light-cone wave functions for the involved baryons we are able
to predict cross sections and spin correlation parameters for the process of
interest.Comment: 39 pages, 7 figures, problems with printout of figures resolved, Ref.
33 and referring sentences in section 4 change
Search for Invisible Decays of and in and
Using a data sample of decays collected with the BES
II detector at the BEPC, searches for invisible decays of and
in to and are performed.
The signals, which are reconstructed in final states, are used
to tag the and decays. No signals are found for the
invisible decays of either or , and upper limits at the 90%
confidence level are determined to be for the ratio
and for . These are the first
searches for and decays into invisible final states.Comment: 5 pages, 4 figures; Added references, Corrected typo
Quantum optical coherence tomography with dispersion cancellation
We propose a new technique, called quantum optical coherence tomography
(QOCT), for carrying out tomographic measurements with dispersion-cancelled
resolution. The technique can also be used to extract the frequency-dependent
refractive index of the medium. QOCT makes use of a two-photon interferometer
in which a swept delay permits a coincidence interferogram to be traced. The
technique bears a resemblance to classical optical coherence tomography (OCT).
However, it makes use of a nonclassical entangled twin-photon light source that
permits measurements to be made at depths greater than those accessible via
OCT, which suffers from the deleterious effects of sample dispersion. Aside
from the dispersion cancellation, QOCT offers higher sensitivity than OCT as
well as an enhancement of resolution by a factor of 2 for the same source
bandwidth. QOCT and OCT are compared using an idealized sample.Comment: 19 pages, 4 figure
Twisted Backgrounds, PP-Waves and Nonlocal Field Theories
We study partially supersymmetric plane-wave like deformations of string
theories and M-theory on brane backgrounds. These deformations are dual to
nonlocal field theories. We calculate various expectation values of
configurations of closed as well as open Wilson loops and Wilson surfaces in
those theories. We also discuss the manifestation of the nonlocality structure
in the supergravity backgrounds. A plane-wave like deformation of little string
theory has also been studied.Comment: 46 pages, changed to JHEP forma
Computing the first eigenpair of the p-Laplacian via inverse iteration of sublinear supersolutions
We introduce an iterative method for computing the first eigenpair
for the -Laplacian operator with homogeneous Dirichlet
data as the limit of as , where
is the positive solution of the sublinear Lane-Emden equation
with same boundary data. The method is
shown to work for any smooth, bounded domain. Solutions to the Lane-Emden
problem are obtained through inverse iteration of a super-solution which is
derived from the solution to the torsional creep problem. Convergence of
to is in the -norm and the rate of convergence of
to is at least . Numerical evidence is
presented.Comment: Section 5 was rewritten. Jed Brown was added as autho
- …