132 research outputs found
Realistic shell-model calculations for proton particle-neutron hole nuclei around 132Sn
We have performed shell-model calculations for nuclei with proton particles
and neutron holes around 132Sn using a realistic effective interaction derived
from the CD-Bonn nucleon-nucleon potential. For the proton-neutron channel this
is explicitly done in the particle-hole formalism. The calculated results are
compared with the available experimental data, particular attention being
focused on the proton particle-neutron hole multiplets. A very good agreement
is obtained for all the four nuclei considered, 132Sb, 130Sb, 133Te and 131Sb.
We predict many low-energy states which have no experimental counterpart. This
may stimulate, and be helpful to, future experiments.Comment: 8 pages, 6 figures, to be published on Physical Review
Proton-Neutron Interaction near Closed Shells
Odd-odd nuclei around double shell closures are a direct source of
information on the proton-neutron interaction between valence nucleons. We have
performed shell-model calculations for doubly odd nuclei close to Pb,
Sn and Sn using realistic effective interactions derived from
the CD-Bonn nucleon-nucleon potential. The calculated results are compared with
the available experimental data, attention being focused on particle-hole and
particle-particle multiplets. While a good agreement is obtained for all the
nuclei considered, a detailed analysis of the matrix elements of the effective
interaction shows that a stronger core-polarization contribution seems to be
needed in the particle-particle case.Comment: 8 pages, 6 figures, Proccedings of the International Conference
"Nuclear Structure and Related Topics", Dubna, Russia, September 2-6, 2003,
to be published in Yadernaia Fizika (Physics of Atomic Nuclei
Evolution of the solar irradiance during the Holocene
Aims. We present a physically consistent reconstruction of the total solar
irradiance for the Holocene. Methods. We extend the SATIRE models to estimate
the evolution of the total (and partly spectral) solar irradiance over the
Holocene. The basic assumption is that the variations of the solar irradiance
are due to the evolution of the dark and bright magnetic features on the solar
surface. The evolution of the decadally averaged magnetic flux is computed from
decadal values of cosmogenic isotope concentrations recorded in natural
archives employing a series of physics-based models connecting the processes
from the modulation of the cosmic ray flux in the heliosphere to their record
in natural archives. We then compute the total solar irradiance (TSI) as a
linear combination of the jth and jth + 1 decadal values of the open magnetic
flux. Results. Reconstructions of the TSI over the Holocene, each valid for a
di_erent paleomagnetic time series, are presented. Our analysis suggests that
major sources of uncertainty in the TSI in this model are the heritage of the
uncertainty of the TSI since 1610 reconstructed from sunspot data and the
uncertainty of the evolution of the Earth's magnetic dipole moment. The
analysis of the distribution functions of the reconstructed irradiance for the
last 3000 years indicates that the estimates based on the virtual axial dipole
moment are significantly lower at earlier times than the reconstructions based
on the virtual dipole moment. Conclusions. We present the first physics-based
reconstruction of the total solar irradiance over the Holocene, which will be
of interest for studies of climate change over the last 11500 years. The
reconstruction indicates that the decadally averaged total solar irradiance
ranges over approximately 1.5 W/m2 from grand maxima to grand minima
Charge-radius change and nuclear moments in the heavy tin isotopes from laser spectroscopy: Charge radius of Sn
NESTER ACCLaser spectroscopy measurements have been carried out on the neutron-rich tin isotopes with the COMPLIS experimental setup. Using the optical transition, hyperfine spectra of Sn and were recorded for the first time. The nuclear moments and the mean square charge radius variation (\delta, the absolute charge radii of these isotopes were deduced in particular that of the doubly magic Sn nucleus. The comparison of the results with several mean-field-type calculations have shown that dynamical effects play an important role in the tin isotopes
Recent results on neutron rich tin isotopes by laser spectroscopy
Laser spectroscopy measurements have been performed on neutron rich tin isotopes using the COMPLIS experimental setup. The nuclear charge radii of the even-even isotopes from A=108 to 132 are compared to the results of macroscopic and microscopic calculations. The improvements and optimizations needed to perform the isotope shift measurement on Sn are presented
Magnetic properties and archeointensity determination on Pre-Columbian pottery from Chiapas, Mesoamerica
Updated Iberian archeomagnetic catalogue: new full vector paleosecular variation curve for the last three millennia
In this work, we present 16 directional and 27 intensity high‐quality values from Iberia. Moreover, we have updated the Iberian archeomagnetic catalogue published more than 10 years ago with a considerable increase in the database. This has led to a notable improvement of both temporal and spatial data distribution. A full vector paleosecular variation curve from 1000 BC to 1900 AD has been developed using high‐quality data within a radius of 900 km from Madrid. A hierarchical bootstrap method has been followed for the computation of the curves. The most remarkable feature of the new curves is a notable intensity maximum of about 80 μT around 600 BC, which has not been previously reported for the Iberian Peninsula. We have also analyzed the evolution of the paleofield in Europe for the last three thousand years and conclude that the high maximum intensity values observed around 600 BC in the Iberian Peninsula could respond to the same feature as the Levantine Iron Age Anomaly, after travelling westward through Europe
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