201 research outputs found
Neutron density distribution and neutron skin thickness of Pb
We present and discuss numerical predictions for the neutron density
distribution of Pb using various non-relativistic and relativistic
mean-field models for the nuclear structure. Our results are compared with the
very recent pion photoproduction data from Mainz. The parity-violating
asymmetry parameter for elastic electron scattering at the kinematics of the
PREX experiment at JLab and the neutron skin thickness are compared with the
available data. We consider also the dependence between the neutron skin and
the parameters of the expansion of the symmetry energy.Comment: 9 pages, 6 figures, latest MAMI data use
Elastic and quasi-elastic electron scattering off nuclei with neutron excess
We present theoretical predictions for electron scattering on oxygen and
calcium isotopic chains. The calculations are done within the framework of the
distorted-wave Born approximation and the proton and neutron density
distributions are evaluated adopting a relativistic Dirac-Hartree model. We
present results for the elastic and quasi-elastic cross sections and for the
parity-violating asymmetry. As a first step, the results of the models are
tested in comparison with some of the data available for elastic and
quasi-elastic scattering on 16O and 40Ca nuclei. Then, the evolution of some
nuclear properties is investigated as a function of the neutron number. We also
present a comparison with the parity-violating asymmetry parameter obtained by
the PREX Collaboration on 208Pb and give a prediction for the future experiment
CREX on 48Ca.Comment: 37 pages, 17 figures. version accepted for publication in the
Physical Review C. arXiv admin note: text overlap with arXiv:0809.4124 by
other author
TRAMPLE: the transmembrane protein labelling environment
TRAMPLE () is a web application server dedicated to the detection and the annotation of transmembrane protein sequences. TRAMPLE includes different state-of-the-art algorithms for the prediction of signal peptides, transmembrane segments (both beta-strands and alpha-helices), secondary structure and fast fold recognition. TRAMPLE also includes a complete content management system to manage the results of the predictions. Each user of the server has his/her own workplace, where the data can be stored, organized, accessed and annotated with documents through a simple web-based interface. In this manner, TRAMPLE significantly improves usability with respect to other more traditional web servers
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