9,321 research outputs found
Non-spectator Contributions To The Lifetime of
In this work, we evaluate the contributions of non-spectator effects to the
lifetimes of and B-mesons. Based on the well-established models and
within a reasonable range of the concerned parameters, the contributions can
reduce the lifetime of by compared to that of B-mesons
which are not significantly affected. This might partly explain the measured
ratio \cite{Data}, which has been a
long-standing discrepancy between theory and experimental data
The pseudocomplementedness of modular lattices and its applications in groups
In this article, we first investigate pseudocomplemented inductive modular
lattices by using their a finite number of 0-sublattices. Then we use a finite
number of the 0-sublattices of a subgroup lattice to describe all locally
cyclic abelian groups. The results show us that a locally cyclic abelian group
can be characterized by its three number of subgroups.Comment:
Multi-Estimator Full Left Ventricle Quantification through Ensemble Learning
Cardiovascular disease accounts for 1 in every 4 deaths in United States.
Accurate estimation of structural and functional cardiac parameters is crucial
for both diagnosis and disease management. In this work, we develop an ensemble
learning framework for more accurate and robust left ventricle (LV)
quantification. The framework combines two 1st-level modules: direct estimation
module and a segmentation module. The direct estimation module utilizes
Convolutional Neural Network (CNN) to achieve end-to-end quantification. The
CNN is trained by taking 2D cardiac images as input and cardiac parameters as
output. The segmentation module utilizes a U-Net architecture for obtaining
pixel-wise prediction of the epicardium and endocardium of LV from the
background. The binary U-Net output is then analyzed by a separate CNN for
estimating the cardiac parameters. We then employ linear regression between the
1st-level predictor and ground truth to learn a 2nd-level predictor that
ensembles the results from 1st-level modules for the final estimation.
Preliminary results by testing the proposed framework on the LVQuan18 dataset
show superior performance of the ensemble learning model over the two base
modules.Comment: Jiasha Liu, Xiang Li and Hui Ren contribute equally to this wor
Diquarks and the Semi-Leptonic Decay of in the Hybrid Scheme
In this work we use the heavy-quark-light-diquark picture to study the
semileptonic decay in the so-called
hybrid scheme. Namely, we apply the heavy quark effective theory (HQET) for
larger (corresponding to small recoil), which is the invariant mass
square of , whereas the perturbative QCD approach for smaller
to calculate the form factors. The turning point where we require the form
factors derived in the two approaches to be connected, is chosen near
. It is noted that the kinematic parameter which is
usually adopted in the perturbative QCD approach, is in fact exactly the same
as the recoil factor used in HQET where , are the
four velocities of and respectively. We find that the
final result is not much sensitive to the choice, so that it is relatively
reliable. Moreover, we apply a proper numerical program within a small range
around to make the connection sufficiently smooth and we
parameterize the form factor by fitting the curve gained in the hybrid scheme.
The expression and involved parameters can be compared with the ones gained by
fitting the experimental data. In this scheme the end-point singularities do
not appear at all. The calculated value is satisfactorily consistent with the
data which is recently measured by the DELPHI collaboration within two standard
deviations.Comment: 16 pages, including 4 figures, revtex
Lifshitz Scaling Effects on Holographic Superconductors
Via numerical and analytical methods, the effects of the Lifshitz dynamical
exponent on holographic superconductors are studied in some detail,
including wave and wave models. Working in the probe limit, we find
that the behaviors of holographic models indeed depend on concrete value of
. We obtain the condensation and conductivity in both Lifshitz black hole
and soliton backgrounds with general . For both wave and wave models
in the black hole backgrounds, as increases, the phase transition becomes
more difficult and the growth of conductivity is suppressed. For the Lifshitz
soliton backgrounds, when increases (), the critical chemical
potential decreases in the wave cases but increases in the wave cases.
For wave models in both Lifshitz black hole and soliton backgrounds, the
anisotropy between the AC conductivity in different spatial directions is
suppressed when increases. The analytical results uphold the numerical
results.Comment: Typos corrected; Footnote added; References added; To be published in
Nuclear Physics
- …