61,960 research outputs found
Pure spinor computation towards open string three-loop
Using the recent results in the pure spinor formulation, we lay out a
ground-work towards the full momentum space amplitudes of open superstrings at
three-loop. After briefly reviewing the one-loop amplitude, we directly work
out the two-loop and reproduce the result that was obtained by a symmetry
argument. For the three-loop, first we use the two-loop regulator as a warm-up
exercise. The result vanishes. We then employ the regulator that has been
recently proposed by Aisaka and Berkovits (AB). It is noted that the terms in
higher power in that render the two-loop
regulator disqualified for the three-loop do not contribute. This with a few
other indications suggests a possibility that the AB regulator might also lead
to a vanishing result. Nevertheless, we argue that it is possible to acquire
the three-loop amplitude, and present a result that we anticipate to be the
three-loop amplitude.Comment: 41 pages, latex, cosmetic change
Principal Component Analysis of Cavity Beam Position Monitor Signals
Model-independent analysis (MIA) methods are generally useful for analysing
complex systems in which relationships between the observables are non-trivial
and noise is present. Principle Component Analysis (PCA) is one of MIA methods
allowing to isolate components in the input data graded to their contribution
to the variability of the data. In this publication we show how the PCA can be
applied to digitised signals obtained from a cavity beam position monitor
(CBPM) system on the example of a 3-cavity test system installed at the
Accelerator Test Facility 2 (ATF2) at KEK in Japan. We demonstrate that the PCA
based method can be used to extract beam position information, and matches
conventional techniques in terms of performance, while requiring considerably
less settings and data for calibration
Partial Teleportation of Entanglement in the Noisy Environment
Partial teleportation of entanglement is to teleport one particle of an
entangled pair through a quantum channel. This is conceptually equivalent to
quantum swapping. We consider the partial teleportation of entanglement in the
noisy environment, employing the Werner-state representation of the noisy
channel for the simplicity of calculation. To have the insight of the many-body
teleportation, we introduce the measure of correlation information and study
the transfer of the correlation information and entanglement. We find that the
fidelity gets smaller as the initial-state is entangled more for a given
entanglement of the quantum channel. The entangled channel transfers at least
some of the entanglement to the final state.Comment: 8 pages, 2 figure
A predictive standard model for heavy electron systems
We propose a predictive standard model for heavy electron systems based on a
detailed phenomenological two-fluid description of existing experimental data.
It leads to a new phase diagram that replaces the Doniach picture, describes
the emergent anomalous scaling behavior of the heavy electron (Kondo) liquid
measured below the lattice coherence temperature, T*, seen by many different
experimental probes, that marks the onset of collective hybridization, and
enables one to obtain important information on quantum criticality and the
superconducting/antiferromagnetic states at low temperatures. Because T* is
~J^2\rho/2, the nearest neighbor RKKY interaction, a knowledge of the
single-ion Kondo coupling, J, to the background conduction electron density of
states, \rho, makes it possible to predict Kondo liquid behavior, and to
estimate its maximum superconducting transition temperature in both existing
and newly discovered heavy electron families.Comment: 4 pages, 2 figures, submitted to J. Phys.: Conf. Ser. for SCES 201
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