1,082 research outputs found
Eta-meson production in the resonance energy region
We perform an updated coupled-channel analysis of eta-meson production
including all recent photoproduction data on the proton. The dip observed in
the differential cross sections at c.m. energies W=1.68 GeV is explained by
destructive interference between the and states.
The effect from is found to be small but still important to
reproduce the correct shape of the differential cross section.
For the scattering we suggest a reaction mechanism in
terms of the , , and states. Our
conclusion on the importance of the , , and
resonances in the eta-production reactions is in line with our
previous results. No strong indication for a narrow state with a width of 15
MeV and the mass of 1680 MeV is found in the analysis. scattering
length is extracted and discussed.Comment: replaced with a published version, pole parameters and scattering
lengths are adde
The Symmetries of Nature
The study of the symmetries of nature has fascinated scientists for eons. The application of the formal mathematical description of
symmetries during the last century has produced many breakthroughs in
our understanding of the substructure of matter. In this talk, a number
of these advances are discussed, and the important role that George
Sudarshan played in their development is emphasize
Analysis of electroencephalograms in Alzheimer's disease patients with multiscale entropy
The aim of this study was to analyse the electroencephalogram (EEG) background activity of Alzheimer’s disease (AD) patients using the Multiscale Entropy (MSE). The MSE is a recently developed method that quantifies the regularity of a signal on different time scales. These time scales are inspected by means of several coarse-grained sequences formed from the analysed signals. We recorded the EEGs from 19 scalp electrodes in 11 AD patients and 11 age-matched controls and estimated the MSE profile for each epoch of the EEG recordings. The shape of the MSE profiles reveals the EEG complexity, and it suggests that the EEG contains information in deeper scales than the smallest one. Moreover, the results showed that the EEG background activity is less complex in AD patients than control subjects. We found significant difference
Reply to "Comment on 'Analysis of electroencephalograms in Alzheimer's disease patients with multiscale entropy'"
We appreciate the interest of Dr Tang in our article. Certainly, our previous results should be taken with caution due to the small database size. Nevertheless, it must be noted that this limitation was clearly recognized in our article. Furthermore, our hypothesis is completely justified from the current state of the art in the analysis of electroencephalogram (EEG) signals from Alzheimer's disease (AD) patients. We evaluated whether the multiscale entropy (MSE) analysis of the EEG background activity was useful to distinguish AD patients and controls. We do believe that further discussions about risk factors or related clinicophysiological protein aspects are clearly beyond the scope of our article. For the sake of completeness, we now detail some results that complement our previous analysis. They suggest that the MSE analysis can provide relevant information about the dynamics of AD patients' EEG data. Thus, we must reaffirm our conclusions, although we again acknowledge that further studies are needed
On Muddled Methods and Their Meaning
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68431/2/10.1177_048661346900100105.pd
Strangeness Content in the Nucleon
I review recent studies of strangeness content in the nucleon pertaining to
the flavor-singlet , the matrix element and the strangeness
electric and magnetic form factors and , based on
lattice QCD calculations. I shall also discuss the relevance of incorporating
the strangeness content in nuclei in regard to strange baryon-antibaryon
productions from proton-nucleus and nucleus-nucleus collisions at SPS and RHIC
energies.Comment: 11 pages, 4 figures, Invited talk at V Int. Conf. on Strangeness in
Quark Matter, Berkeley, CA, July 20--25, 200
Phi meson production in In-In collisions at =158 GeV: evidence for relics of a thermal phase
Yields and transverse mass distributions of the -mesons reconstructed
in the channel in In+In collisions at =158
GeV are calculated within an integrated Boltzmann+hydrodynamics hybrid approach
based on the Ultrarelativistic Quantum Molecular Dynamics (UrQMD) transport
model with an intermediate hydrodynamic stage. The analysis is performed for
various centralities and a comparison with the corresponding NA60 data in the
muon channel is presented. We find that the hybrid model, that embeds an
intermediate locally equilibrated phase subsequently mapped into the transport
dynamics according to thermal phase-space distributions, gives a good
description of the experimental data, both in yield and slope. On the contrary,
the pure transport model calculations tend to fail in catching the general
properties of the meson production: not only the yield, but also the
slope of the spectra, very poorly compare with the experimental
observations
Changing distribution of the east coast of Scotland bottlenose dolphin population and the challenges of area‐based management
MAC received funding from the Department of Energy and Climate Change (DECC) (now Department for Business, Energy and Industrial Strategy) UK, and the MASTS (Marine Alliance for Science and Technology for Scotland) pooling initiative. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. Annual surveys were funded by DECC, Scottish Natural Heritage (SNH), Beatrice Offshore Windfarm Ltd., Moray Offshore Renewables Ltd, Marine Scotland, The Crown Estate, Highlands and Islands Enterprise and the Universities of St Andrews and Aberdeen. All fieldwork was carried out under SNH Animal Scientific Licences to PMT and PSH. The authors have no conflict of interest to declare. We thank John Baxter for helpful discussions about the implications for conservation and management while drafting this manuscript, and Morven Carruthers for her advice on the site condition monitoring for the Moray Firth SAC. This manuscript benefited from the helpful comments of two anonymous reviewers.Peer reviewedPostprin
Quark-model study of few-baryon systems
We review the application of non-relativistic constituent quark models to
study one, two and three non-strange baryon systems. We present results for the
baryon spectra, potentials and observables of the NN, N,
and NN systems, and also for the binding energies of three
non-strange baryon systems. We make emphasis on observable effects related to
quark antisymmetry and its interplay with quark dynamics.Comment: 82 pages, 36 figures, 18 tables. Accepted for publication in Reports
on Progress in Physic
History of exotic Meson (4-quark) and Baryon (5-quark) States
I briefly review the history of exotic meson (4-quark) and baryon (5-quark)
states, which is rooted in the formalism of Regge pole and duality. There are
robust model-independent predictions for the exchange of 4-quark (Baryonium)
Regge trajectories in several processes, which are strongly supported by
experiment. On the other hand the predictions for the spectroscopy of 4-quark
resonances are based on specific QCD inspired models, with some experimental
support. The corresponding predictions for the recently discovered exotic
baryon (Pentaquark) state are briefly discussed.Comment: 14 pages Latex including 4 eps figures, final version to appear as a
topical review in J. Phys.
- …