79,422 research outputs found
Conditions for Nondistortion Interrogation of Quantum System
Under some physical considerations, we present a universal formulation to
study the possibility of localizing a quantum object in a given region without
disturbing its unknown internal state. When the interaction between the object
and probe wave function takes place only once, we prove the necessary and
sufficient condition that the object's presence can be detected in an initial
state preserving way. Meanwhile, a conditioned optimal interrogation
probability is obtained.Comment: 5 pages, Revtex, 1 figures, Presentation improved, corollary 1 added.
To appear in Europhysics Letter
Scalars in the hadron world: the Higgs sector of the strong interaction
Scalar mesons are a key expression of the strong physics regime of QCD and
the role condensates, particularly , play in breaking chiral
symmetry.
What new insights have been provided by recent experiments on and
decays to light hadrons is discussed. We need to establish whether all
the claimed scalars , , , etc., really exist and
with what parameters before we can meaningfully speculate further about which
is transiently , , multi-meson molecule or largely
glue.Comment: 10 pages, 4 figures. Invited talk at the International Conference on
QCD and Hadronic Physics, Beijing, June 2005. A shortened version will appear
in the Proceeding
Effect of Dzyaloshinskii Moriya interaction on magnetic vortex
The effect of the Dzyaloshinskii Moriya interaction on the vortex in magnetic
microdisk was investigated by micro magnetic simulation based on the Landau
Lifshitz Gilbert equation. Our results show that the DM interaction modifies
the size of the vortex core, and also induces an out of plane magnetization
component at the edge and inside the disk. The DM interaction can destabilizes
one vortex handedness, generate a bias field to the vortex core and couple the
vortex polarity and chirality. This DM-interaction-induced coupling can
therefore provide a new way to control vortex polarity and chirality
Hamiltonicity of 3-arc graphs
An arc of a graph is an oriented edge and a 3-arc is a 4-tuple of
vertices such that both and are paths of length two. The
3-arc graph of a graph is defined to have vertices the arcs of such
that two arcs are adjacent if and only if is a 3-arc of
. In this paper we prove that any connected 3-arc graph is Hamiltonian, and
all iterative 3-arc graphs of any connected graph of minimum degree at least
three are Hamiltonian. As a consequence we obtain that if a vertex-transitive
graph is isomorphic to the 3-arc graph of a connected arc-transitive graph of
degree at least three, then it is Hamiltonian. This confirms the well known
conjecture, that all vertex-transitive graphs with finitely many exceptions are
Hamiltonian, for a large family of vertex-transitive graphs. We also prove that
if a graph with at least four vertices is Hamilton-connected, then so are its
iterative 3-arc graphs.Comment: in press Graphs and Combinatorics, 201
Finite-dimensional integrable systems associated with Davey-Stewartson I equation
For the Davey-Stewartson I equation, which is an integrable equation in 1+2
dimensions, we have already found its Lax pair in 1+1 dimensional form by
nonlinear constraints. This paper deals with the second nonlinearization of
this 1+1 dimensional system to get three 1+0 dimensional Hamiltonian systems
with a constraint of Neumann type. The full set of involutive conserved
integrals is obtained and their functional independence is proved. Therefore,
the Hamiltonian systems are completely integrable in Liouville sense. A
periodic solution of the Davey-Stewartson I equation is obtained by solving
these classical Hamiltonian systems as an example.Comment: 18 pages, LaTe
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