1,032 research outputs found
Solitons in systems of coupled scalar fields
We present a method to obtain soliton solutions to relativistic system of
coupled scalar fields. This is done by examining the energy associated to
static field configurations. In this case we derive a set of first-order
differential equations that solve the equations of motion when the energy
saturates its lower bound. To illustrate the general results, we investigate
some systems described by polynomial interactions in the coupled fields.Comment: RevTex4, 5 page
CP violation in the effective action of the Standard Model
Following a suggestion by Smit, the CP odd terms of the effective action of
the Standard Model, obtained by integration of quarks and leptons, are computed
to sixth order within a strict covariant derivative expansion approach. No
other approximations are made. The final result so derived includes all
Standard Model gauge fields and Higgs. Remarkably, at the order considered in
this work, all parity violating contributions turn out to be zero. Non
vanishing CP violating terms are obtained in the C-odd P-even sector. These are
several orders of magnitude larger than perturbative estimates. Various
unexpected regularities in the final result are noted.Comment: 32 pages, no figures. Section added. To appear in JHE
Dielectron Measurements in STAR
Ultrarelativistic heavy-ion collisions provide a unique environment to study
the properties of strongly interacting matter. Dileptons, which are not
affected by the strong interactions, are an ideal penetrating probe. We present
the dielectron results for p+p and Au+Au collisions at \sqrt{s_\mathrm{NN}}}
=200 GeV, as measured by the STAR experiment. We discuss the prospects of
dilepton measurements with the near-future detector upgrades, and the recent
lower beam energy Au+Au measurements.Comment: Resonance Workshop at UT Austin (2012), 8 pages,15 figure
Word matching using single closed contours for indexing handwritten historical documents
Effective indexing is crucial for providing convenient access to scanned versions of large collections of historically valuable handwritten manuscripts. Since traditional handwriting recognizers based on optical character recognition (OCR) do not perform well on historical documents, recently a holistic word recognition approach has gained in popularity as an attractive and more straightforward solution (Lavrenko et al. in proc. document Image Analysis for Libraries (DIALâ04), pp. 278â287, 2004). Such techniques attempt to recognize words based on scalar and profile-based features extracted from whole word images. In this paper, we propose a new approach to holistic word recognition for historical handwritten manuscripts based on matching word contours instead of whole images or word profiles. The new method consists of robust extraction of closed word contours and the application of an elastic contour matching technique proposed originally for general shapes (Adamek and OâConnor in IEEE Trans Circuits Syst Video Technol 5:2004). We demonstrate that multiscale contour-based descriptors can effectively capture intrinsic word features avoiding any segmentation of words into smaller subunits. Our experiments show a recognition accuracy of 83%, which considerably exceeds the performance of other systems reported in the literature
Properties of a beam splitter entangler with Gaussian input states
An explicit formula is given for the quantity of entanglement in the output
state of a beam splitter, given the squeezed vacuum states input in each mode.Comment: To appear in Phys. Rev.
One-pion transitions between heavy baryons in the constituent quark model
Single pion transitions of S wave to S wave, P wave to S wave and P wave to P
wave heavy baryons are analyzed in the framework of the Heavy Quark Symmetry
limit (HQS). We use a constituent quark model picture for the light diquark
system with an underlying SU(2N_{f}) X O(3) symmetry to reduce the number of
the HQS coupling factors required to describe these transitions. We also use
the quantum theory of angular momentum to rewrite the one-pion transitions
constituent quark model results in a more general form using the 6j- and
9j-symbols. We finally estimate the decay rates of some single pion transitions
between charm baryon states.Comment: Latex, 33 pages including 2 figures (Postscript). Some typos are
corrected with minor changes. Two references were added to the final version
which will appear in Phy. Rev.
Dark solitons in ferromagnetic chains with first- and second-neighbor interactions
We study the ferromagnetic spin chain with both first- and second-neighbor
interactions. We obtained the condition for the appearance and stability of
bright and dark solitons for arbitrary wave number inside the Brillouin zone.
The influence of the second-neighbor interaction and the anisotropy on the
soliton properties is considered. The scattering of dark solitons from point
defects in the discrete spin chain is investigated numerically.Comment: 7 pages,5 figure
Experimental preparation of Werner state via spontaneous parametric down-conversion
We present an experiment of preparing Werner state via spontaneous parametric
down-conversion and controlled decoherence of photons in this paper. In this
experiment two independent BBO (beta-barium borate) crystals are used to
produce down-conversion light beams, which are mixed to prepare Werner state.Comment: 6 pages, 4 figures and 2 table
New production method of convex microlens arrays for integrated fluorescence microfluidic detection systems
A new method for producing microlens array with large sag heights is proposed for integrated fluorescence microfluidic detection systems. Three steps in this production technique are included for concave microlens array formations to be integrated into microfluidic systems. First, using the photoresist SU-8 to produce hexagonal microchannel array is required. Second, UV curable glue is injected into the hexagonal microchannel array. Third, the surplus glue is rotated by a spinner at high velocity and exposed to a UV lamp to harden the glue. The micro concave lens molds are then finished and ready to produce convex microlens in poly methsiloxane (PDMS) material. This convex microlens in PDMS can be used for detecting fluorescence in microfluidic channels because a convex microlens plays the light convergence role for optical fiber detection
Vaginal delivery and serum markers of ischemia/reperfusion injury
Objective: Vaginal deliveries have been associated with pelvic organ prolapse and incontinence. The objective was to show whether markers of ischemia/reperfusion injury are dependent upon the mode of delivery and length of labor. Method: Complete venipuncture sets were obtained on 62 subjects. All samples collected were analyzed for serum creatine phosphokinase (CPK) and lactate dehydrogenase (LDH). Lipid peroxidation was analyzed, using thiobarbituric acid reactive substances (TBARS), on a subset of 37 patients. Results: There was a significant increase in CPK from admission to 1Â h postpartum and postpartum day 1 in vaginal delivery versus cesarean delivery. Longer second stages were associated with significant increases in CPK. There were no significant changes in either LDH or TBARS from admission to any other time point regardless of mode of delivery. Conclusion: Vaginal delivery and longer second stages were associated with a much greater increase in one of these injury markers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135489/1/ijgo96.pd
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