74 research outputs found
Signature inversion in axially deformed Tm
The microscopic analysis of experimental data in Tm is presented
within the two-quasiparticle-phonon model. The model includes the interaction
between odd quasiparticles and their coupling with core vibrations. The
coupling explains naturally the attenuation of the Coriolis interaction in
rotating odd-odd nuclei. It is shown that the competition between the Coriolis
and neutron-proton interactions is responsible for the signature inversion
phenomenon.Comment: 10 pages, 1 figure, corrected some typo
Locally supersymmetric D=3 non-linear sigma models
We study non-linear sigma models with N local supersymmetries in three
space-time dimensions. For N=1 and 2 the target space of these models is
Riemannian or Kahler, respectively. All N>2 theories are associated with
Einstein spaces. For N=3 the target space is quaternionic, while for N=4 it
generally decomposes into two separate quaternionic spaces, associated with
inequivalent supermultiplets. For N=5,6,8 there is a unique (symmetric) space
for any given number of supermultiplets. Beyond that there are only theories
based on a single supermultiplet for N=9,10,12 and 16, associated with coset
spaces with the exceptional isometry groups , ,
and , respectively. For and the
theories obtained by dimensional reduction are two-loop finite.Comment: 35 pages plain tex, CERN-TH.6612/92 THU-92-1
Experimentally feasible measures of distance between quantum operations
We present two measures of distance between quantum processes based on the
superfidelity, introduced recently to provide an upper bound for quantum
fidelity. We show that the introduced measures partially fulfill the
requirements for distance measure between quantum processes. We also argue that
they can be especially useful as diagnostic measures to get preliminary
knowledge about imperfections in an experimental setup. In particular we
provide quantum circuit which can be used to measure the superfidelity between
quantum processes.
As the behavior of the superfidelity between quantum processes is crucial for
the properties of the introduced measures, we study its behavior for several
families of quantum channels. We calculate superfidelity between arbitrary
one-qubit channels using affine parametrization and superfidelity between
generalized Pauli channels in arbitrary dimensions. Statistical behavior of the
proposed quantities for the ensembles of quantum operations in low dimensions
indicates that the proposed measures can be indeed used to distinguish quantum
processes.Comment: 9 pages, 4 figure
An Introduction to Hyperbolic Barycentric Coordinates and their Applications
Barycentric coordinates are commonly used in Euclidean geometry. The
adaptation of barycentric coordinates for use in hyperbolic geometry gives rise
to hyperbolic barycentric coordinates, known as gyrobarycentric coordinates.
The aim of this article is to present the road from Einstein's velocity
addition law of relativistically admissible velocities to hyperbolic
barycentric coordinates along with applications.Comment: 66 pages, 3 figure
Mean-field description of ground-state properties of drip-line nuclei. (I) Shell-correction method
A shell-correction method is applied to nuclei far from the beta stability
line and its suitability to describe effects of the particle continuum is
discussed. The sensitivity of predicted locations of one- and two-particle drip
lines to details of the macroscopic-microscopic model is analyzed.Comment: 22 REVTeX pages, 13 uuencoded postscript figures available upon
reques
Enhanced T-odd P-odd Electromagnetic Moments in Reflection Asymmetric Nuclei
Collective P- and T- odd moments produced by parity and time invariance
violating forces in reflection asymmetric nuclei are considered. The enhanced
collective Schiff, electric dipole and octupole moments appear due to the
mixing of rotational levels of opposite parity. These moments can exceed
single-particle moments by more than two orders of magnitude. The enhancement
is due to the collective nature of the intrinsic moments and the small energy
separation between members of parity doublets. In turn these nuclear moments
induce enhanced T- and P- odd effects in atoms and molecules. First a simple
estimate is given and then a detailed theoretical treatment of the collective
T-, P- odd electric moments in reflection asymmetric, odd-mass nuclei is
presented and various corrections evaluated. Calculations are performed for
octupole deformed long-lived odd-mass isotopes of Rn, Fr, Ra, Ac and Pa and the
corresponding atoms. Experiments with such atoms may improve substantially the
limits on time reversal violation.Comment: 28 pages, Revte
Interplay of pairing and multipole interactions in a simple model
The interplay of pairing and other interactions is addressed in this work
using a simple single-j model. We show that enhancements in pairing
correlations observed through studies of the spectra of deformed systems,
moments of inertia, changes in transitional multipole amplitudes, and direct
calculations of the pairing component in the wave function, indicate that even
without explicit matrix elements responsible for pairing, a paired state can
still appear from the kinematic coupling of pairing to deformation and from
other geometrical restrictions that are of extreme importance in mesoscopic
systems. Furthermore, we demonstrate that macroscopic transitions such as
oblate to prolate shape changes can lead to strong dynamic enhancements of
pairing correlations. In this work we emphasize that the pairing condensate has
an important dynamic and kinematic effect on other residual interactions.Comment: 39 pages, 8 figure
Consistent interactions of dual linearized gravity in D=5: couplings with a topological BF model
Under some plausible assumptions, we find that the dual formulation of
linearized gravity in D=5 can be nontrivially coupled to the topological BF
model in such a way that the interacting theory exhibits a deformed gauge
algebra and some deformed, on-shell reducibility relations. Moreover, the
tensor field with the mixed symmetry (2,1) gains some shift gauge
transformations with parameters from the BF sector.Comment: 63 pages, accepted for publication in Eur. Phys. J.
Mass Splitting and Production of and Measured in N Interactions
From a sample of decaying to the
final state, we have observed, in the hadroproduction experiment E791 at
Fermilab, and through
their decays to . The mass difference ) is measured to be ; for
, we find .
The rate of production from decays of the triplet is
(22\pm 2\pm 3) {%} of the total production assuming equal rate
of production from all three, as measured for and .
We do not observe a statistically significant baryon-antibaryon
production asymmetry. The and spectra of from
decays are observed to be similar to those for all 's
produced.Comment: 15 pages, uuencoded postscript 3 figures uuencoded, tar-compressed
fil
Many body physics from a quantum information perspective
The quantum information approach to many body physics has been very
successful in giving new insight and novel numerical methods. In these lecture
notes we take a vertical view of the subject, starting from general concepts
and at each step delving into applications or consequences of a particular
topic. We first review some general quantum information concepts like
entanglement and entanglement measures, which leads us to entanglement area
laws. We then continue with one of the most famous examples of area-law abiding
states: matrix product states, and tensor product states in general. Of these,
we choose one example (classical superposition states) to introduce recent
developments on a novel quantum many body approach: quantum kinetic Ising
models. We conclude with a brief outlook of the field.Comment: Lectures from the Les Houches School on "Modern theories of
correlated electron systems". Improved version new references adde
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