1,022 research outputs found
Rates for the reactions antiproton-proton --> pi phi and gamma phi
We study antiproton-proton annihilation at rest into and
. Rescattering by and
for states is sizable, of
order in the branching ratio, but
smaller than experiment. For the
rescattering contributions are negligible, but the channel is well
explained by a intermediate state combined with vector meson
dominance.Comment: 12 pages, plain latex, 2 postscript figures available upon request,
PSI-PR-93-2
The Use of Dispersion Relations in the and Coupled-Channel System
Systematic and careful studies are made on the properties of the IJ=00
and coupled-channel system, using newly derived dispersion
relations between the phase shifts and poles and cuts. The effects of nearby
branch point singularities to the determination of the resonance are
estimated and and discussed.Comment: 22 pages with 5 eps figures. A numerical bug in previous version is
fixed, discussions slightly expanded. No major conclusion is change
Branching Ratio and CP Asymmetry of B_s \to K^*_0(1430)\pi Decays in the PQCD Approach
In the two-quark model supposition for , the branching ratios
and the direct CP-violating asymmetries for decays are studied by employing the
perturbative QCD factorization approach. We find that although these two decays
are both tree-dominated, the ratio of their penguin to tree contributions are
very different: there is only a few percent for the decay , while about 37% in scenario I, even 51% in scenario II
for the decay . It results that these two
decays have very different values in the branching ratios and the direct CP
asymmetries. The branching ratio of the decay is at the order of , and its direct CP asymmetry
is about (20-30)%. While for the decay , its
direct CP-violating asymmetry is very large and about 90%, but it is difficult
to measure it, because the branching ratio for this channel is small and only
order.Comment: 8pages, 2figure
Systematic Theoretical Search for Dibaryons in a Relativistic Model
A relativistic quark potential model is used to do a systematic search for
quasi-stable dibaryon states in the , , and three flavor world.
Flavor symmetry breaking and channel coupling effects are included and an
adiabatic method and fractional parentage expansion technique are used in the
calculations. The relativistic model predicts dibaryon candidates completely
consistent with the nonrelativistic model.Comment: 12 pages, latex, no figure
HKF: Hierarchical Kalman Filtering with Online Learned Evolution Priors for Adaptive ECG Denoising
Electrocardiography (ECG) signals play a pivotal role in many healthcare
applications, especially in at-home monitoring of vital signs. Wearable
technologies, which these applications often depend upon, frequently produce
low-quality ECG signals. While several methods exist for ECG denoising to
enhance signal quality and aid clinical interpretation, they often underperform
with ECG data from wearable technology due to limited noise tolerance or
inadequate flexibility in capturing ECG dynamics. This paper introduces HKF, a
hierarchical and adaptive Kalman filter, which uses a proprietary state space
model to effectively capture both intra- and inter-heartbeat dynamics for ECG
signal denoising. HKF learns a patient-specific structured prior for the ECG
signal's intra-heartbeat dynamics in an online manner, resulting in a filter
that adapts to the specific ECG signal characteristics of each patient. In an
empirical study, HKF demonstrated superior denoising performance (reduced
mean-squared error) while preserving the unique properties of the waveform. In
a comparative analysis, HKF outperformed previously proposed methods for ECG
denoising, such as the model-based Kalman filter and data-driven autoencoders.
This makes it a suitable candidate for applications in extramural healthcare
settings.Comment: Submitted to Transactions on Signal Processin
Universal Scaling of Wave Propagation Failure in Arrays of Coupled Nonlinear Cells
We study the onset of the propagation failure of wave fronts in systems of
coupled cells. We introduce a new method to analyze the scaling of the critical
external field at which fronts cease to propagate, as a function of
intercellular coupling. We find the universal scaling of the field throughout
the range of couplings, and show that the field becomes exponentially small for
large couplings. Our method is generic and applicable to a wide class of
cellular dynamics in chemical, biological, and engineering systems. We confirm
our results by direct numerical simulations.Comment: 4 pages, 3 figures, RevTe
Mutations in the C-terminal region of the HIV-1 reverse transcriptase and their correlation with drug resistance associated mutations and antiviral treatment
<p>Abstract</p> <p>Objective</p> <p>Replication of HIV-1 after cell entry is essentially dependent on the reverse transcriptase (RT). Antiretroviral drugs impairing the function of the RT currently aim at the polymerase subunit. One reason for failure of antiretroviral treatment is the evolvement of resistance-associated mutations in the viral genome. For RT inhibitors, almost all identified mutations are located within the polymerase; therefore, general genotyping confines to investigate this subunit. Recently several studies have shown that substitutions within the RNase H and the connection domain increase antiviral drug-resistance in vitro, and some of them are present in patient isolates.</p> <p>Aim</p> <p>The aim of the present study was to investigate the prevalence of these substitutions and their association with mutations in the polymerase domain arising during antiretroviral treatment.</p> <p>Materials and methods</p> <p>We performed genotypic analyzes on seventy-four virus isolates derived from treated and untreated patients, followed at the HIV Centre of the Johann Wolfgang Goethe University Hospital (Frankfurt/Main, Germany). We subsequently analysed the different substitutions in the c-terminal region to evaluate whether there were associations with each other, n-terminal substitutions or with antiretroviral treatment.</p> <p>Results</p> <p>We identified several primer grip substitutions, but almost all of them were located in the connection domain. This is consistent with other in-vivo studies, in which especially the primer grip residues located in the RNase H were unvaried. Furthermore, we identified other substitutions in the connection domain and in the RNase H. Especially E399D seemed to be associated with an antiretroviral treatment and N-terminal resistance-delivering mutations.</p> <p>Conclusion</p> <p>Some of the identified substitutions were associated with antiviral treatment and drug resistance-associated mutations. Due to the low prevalence of C-terminal mutations and as only a few of them could be associated with antiviral treatment and N-terminal resistance-delivering mutations, we would not recommend routinely testing of the C-terminal RT region.</p
The detailed mechanism of the eta production in pp scattering up to the Tlab = 4.5 GeV
Contrary to very early beliefs, the experimental cross section data for the
eta production in proton-proton scattering are well described if pi and only
eta meson exchange diagrams are used to calculate the Born term. The inclusion
of initial and final state interactions is done in the factorization
approximation by using the inverse square of the Jost function. The two body
Jost functions are obtained from the S matrices in the low energy effective
range approximation. The danger of double counting in the p-eta final state
interaction is discussed. It is shown that higher partial waves in
meson-nucleon amplitudes do not contribute significantly bellow excess energy
of Q=100 MeV. Known difficulties of reducing the multi resonance model to a
single resonance one are illustrated.Comment: 10 pages, 5 figures, corrected typos in relation (3), changed content
(added section with differential cross sections
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