962 research outputs found
Deuteron-equivalent and phase-equivalent interactions within light nuclei
Background: Phase-equivalent transformations (PETs) are well-known in quantum
scattering and inverse scattering theory. PETs do not affect scattering phase
shifts and bound state energies of two-body system but are conventionally
supposed to modify two-body bound state observables such as the rms radius and
electromagnetic moments. Purpose: In order to preserve all bound state
observables, we propose a new particular case of PETs, a deuteron-equivalent
transformation (DET-PET), which leaves unchanged not only scattering phase
shifts and bound state (deuteron) binding energy but also the bound state wave
function. Methods: The construction of DET-PET is discussed; equations defining
the simplest DET-PETs are derived. We apply these simplest DET-PETs to the
JISP16 interaction and use the transformed interactions in
calculations of H and He binding energies in the No-core Full
Configuration (NCFC) approach based on extrapolations of the No-core Shell
Model (NCSM) basis space results to the infinite basis space. Results: We
demonstrate the DET-PET modification of the scattering wave functions and
study the DET-PET manifestation in the binding energies of H and He
nuclei and their correlation (Tjon line). Conclusions: It is shown that some
DET-PETs generate modifications of the central component while the others
modify the tensor component of the interaction. DET-PETs are able to
modify significantly the scattering wave functions and hence the off-shell
properties of the interaction. DET-PETs give rise to significant changes
in the binding energies of H (in the range of approximately 1.5 MeV) and
He (in the range of more than 9 MeV) and are able to modify the correlation
patterns of binding energies of these nuclei
4q32-q35 and 6q16-q22 are valuable candidate regions for split hand/foot malformation
On the basis of the Human Cytogenetic Database, a computerized catalog of the clinical phenotypes associated with cytogenetically detectable human chromosome aberrations, we collected from the literature 102 cases with chromosomal aberrations and split hand/foot malformation or absent fingers/toes. Statistical analysis revealed a highly significant association (P<0.001) between the malformation and the chromosomal bands 4q32-q35, 5q15, 6q16-q22 and 7q11.2-q22 (SHFM1). Considering these findings, we suggest additional SHFM loci on chromosome 4q, 6q and probably 5q. The regions 4q and 6q have already been discussed in the literature as additional SHFM loci. We now show further evidence. In the proposed regions, there are interesting candidate genes such as, on 4q: HAND2, FGF2, LEF1 and BMPR1B; on 5q: MSX2, FLT4, PTX1 and PDLIM7; and on 6q: SNX3, GJA1, HEY2 and Tbx18.European Journal of Human Genetics advance online publication, 18 February 2009; doi:10.1038/ejhg.2009.11
A Design of a Material Assembly in Space-Time Generating and Storing Energy
The paper introduces a theoretical background of the mechanism of electromagnetic energy and power accumulation and its focusing in narrow pulses travelling along a transmission line with material parameters variable in 1D-space and time. This mechanism may be implemented due to a special material geometry- a distribution of two different dielectrics in a spatio-temporal checkerboard. We concentrate on the practically reasonable means to bring this mechanism into action in a device that may work both as energy generator and energy storage. The basic ideas discussed below appear to be fairly general; we have chosen their electromagnetic implementation as an excellent framework for the entire concept
NN potentials from inverse scattering in the J-matrix approach
An approximate inverse scattering method [7,8] has been used to construct
separable potentials with the Laguerre form factors. As an application, we
invert the phase shifts of proton-proton in the and
channels and neutron-proton in the channel elastic scattering. In
the latter case the deuteron wave function of a realistic potential was
used as input.Comment: LaTex2e, 17 pages, 3 Postscript figures; corrected typo
Electromagnetic multipole moments of elementary spin-1/2, 1, and 3/2 particles
We study multipole decompositions of the electromagnetic currents of
spin-1/2, 1, and 3/2 particles described in terms of Lagrangians designed to
reproduce representation specific wave equations which are second order in the
momenta and which emerge within the recently elaborated Poincar\'e covariant
projector method. We calculate the electric multipoles of the above spins for
the spinor, the four-vector, and the four-vector--spinor representations,
attend to the most general non-Lagrangian spin-3/2 currents which are allowed
by Lorentz invariance to be of third order in the momenta and construct the
linear current equivalent of identical multipole moments of one of them. We
conclude that such non-Lagrangian currents are not necessarily more general
than the two-term currents emerging within the covariant projector method. We
compare our results with those of the conventional Proca-, and Rarita-Schwinger
frameworks. Finally, we test the representation dependence of the multipoles by
placing spin-1 and spin-3/2 in the respective (1,0)(0,1), and
(3/2,0)(0,3/2) single-spin representations. We observe representation
independence of the charge monopoles and the magnetic dipoles, in contrast to
the higher multipoles, which turn out to be representation dependent. In
particular, we find the bi-vector to be characterized by an
electric quadrupole moment of opposite sign to the one found in ,
and consequently, to the boson. Our finding points toward the possibility
that the meson could transform as part of an antisymmetric tensor with
an meson-like state as its representation companion.Comment: 27 pages, 2 figure
Nucleon-nucleon interaction in the -matrix inverse scattering approach and few-nucleon systems
The nucleon-nucleon interaction is constructed by means of the -matrix
version of inverse scattering theory. Ambiguities of the interaction are
eliminated by postulating tridiagonal and quasi-tridiagonal forms of the
potential matrix in the oscillator basis in uncoupled and coupled waves,
respectively. The obtained interaction is very accurate in reproducing the
scattering data and deuteron properties. The interaction is used in the no-core
shell model calculations of H and He nuclei. The resulting binding
energies of H and He are very close to experimental values.Comment: Text is revised, new figures and references adde
Effects of a Commercial Insurance Policy Restriction on Lumbar Fusion in North Carolina and the Implications for National Adoption
Analysis of the State Inpatient Database of North Carolina, 2005–2012, and the Nationwide Inpatient Sample, including all inpatient lumbar fusion admissions from non-federal hospitals
Multi-channel phase-equivalent transformation and supersymmetry
Phase-equivalent transformation of local interaction is generalized to the
multi-channel case. Generally, the transformation does not change the number of
the bound states in the system and their energies. However, with a special
choice of the parameters, the transformation removes one of the bound states
and is equivalent to the multi-channel supersymmetry transformation recently
suggested by Sparenberg and Baye. Using the transformation, it is also possible
to add a bound state to the discrete spectrum of the system at a given energy
if the angular momentum at least in one of the coupled channels .Comment: 9 pages, revtex; to be published in Phys. At. Nucl. (Oct. 2000
Optimization with partial differential equations in dieudonné-rashevsky form and conjugate problems
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46185/1/205_2004_Article_BF00247693.pd
Inverse scattering J-matrix approach to nucleon-nucleus scattering and the shell model
The -matrix inverse scattering approach can be used as an alternative to a
conventional -matrix in analyzing scattering phase shifts and extracting
resonance energies and widths from experimental data. A great advantage of the
-matrix is that it provides eigenstates directly related to the ones
obtained in the shell model in a given model space and with a given value of
the oscillator spacing . This relationship is of a particular
interest in the cases when a many-body system does not have a resonant state or
the resonance is broad and its energy can differ significantly from the shell
model eigenstate. We discuss the -matrix inverse scattering technique,
extend it for the case of charged colliding particles and apply it to the
analysis of and scattering. The results are compared with
the No-core Shell Model calculations of He and Li.Comment: Some text is added following suggestions of a journal refere
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