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J. Barea

Bio: J. Barea is an academic researcher from Spanish National Research Council. The author has contributed to research in topics: Elementary particle & Iterative reconstruction. The author has an hindex of 1, co-authored 3 publications receiving 12 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, a new procedure is presented that combines well-known nuclear models with image reconstruction techniques, where a color-coded image is built by taking the differences between measured masses and the predictions given by the different theoretical models.
Abstract: A new procedure is presented that combines well-known nuclear models with image reconstruction techniques A color-coded image is built by taking the differences between measured masses and the predictions given by the different theoretical models This image is viewed as part of a larger array in the ($N,Z$) plane, where unknown nuclear masses are hidden, covered by a ``mask'' We apply a suitably adapted deconvolution algorithm, used in astronomical observations, to ``open the window'' and see the rest of the pattern We show that it is possible to improve significantly mass predictions in regions not too far from measured nuclear masses

13 citations

Journal ArticleDOI
TL;DR: In this article, low-lying energy states of the isotope chain were studied within the framework of the neutron-proton interacting boson-fermion model (IBFM-2).
Abstract: Low-lying energy states of the ${}^{147\ensuremath{-}153}\text{Pm}$ isotopic chain are studied within the framework of the neutron-proton interacting boson-fermion model (IBFM-2). The spectra of these isotopes show a transition from a particle coupled to a vibrational core to a particle coupled to a deformed one. The calculation reproduces this behavior. In addition, reduced transition probabilities $B(E2)$ and $B(M1)$ and quadrupole and magnetic moments, as well as spectroscopic factors corresponding to stripping and pickup transfer reactions, are calculated. Obtained results compare well with the available experimental data, which reinforces the reliability of the wave functions obtained within the IBFM-2 model.

3 citations

Proceedings ArticleDOI
31 Oct 2007
TL;DR: In this paper, the authors proposed a new method to calculate the nuclear masses of the atomic nucleus using a completely phenomenological point of view, based on the analysis of the differences between measured masses and LDM predictions.
Abstract: Several methods have been developed to calculate and predict nuclear masses over the last 70 years. The accuracy of the present state‐of‐the‐art nuclear mass models is impressive, because these quantities can be calculated with an average 0.05 % precision. However this precision level is still insufficient to deal with nuclear reactions of astrophysical interest, especially r‐process ones. Different approaches exist to calculate nuclear masses, ranging from the simple Bethe‐Weizsacker Liquid Drop Formula (LDM) to the sophisticated Finite Range Droplet Model calculations or the microscopic Hartree‐Fock‐Bogoliuvob techniques from first principles, using Skyrme or Gogny parametrizations of the nucleon‐nucleon interaction. Here we suggest a new method to calculate this fundamental property of the atomic nucleus, using a completely phenomenological point of view. Our method is based in the analysis of the differences between measured masses and LDM predictions, which contains information related to those ingredients not taken into account in the LDM formula, such as shell closures, nuclear deformations and residual nuclear interactions. The differences are arranged in a two dimensional plot which can be viewed as an incomplete image of the full chart of nuclides, equivalent to a product of the full image and a binary mask. In order to remove the distortions produced by this mask we employ an algorithm, well known in astronomy, used to remove artificial effects present in the astrophysical images collected through telescopes. This algorithm is called the CLEAN method. It is one of a number of methods which exists to deconvolve undesirable effects in images and to extrapolate or reconstruct missing parts in them. By using the CLEAN method we can fit measured masses with an r.m.s error of less than 100 keV. We have performed several checks and concluded that its utilization must be carried out carefully in order to obtain reliable results in the zone of unknown masses between the driplines. We also outline potential applications of the present approach.

1 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the authors employed a Bayesian neural network (BNN) approach to improve the nuclear mass predictions of various models and found that the noise error in the likelihood function plays an important role in the predictive performance of the BNN approach.

132 citations

Journal ArticleDOI
TL;DR: With the help of the radial basis function (RBF) and the Garvey-Kelson relation, the accuracy and predictive power of some global nuclear mass models are significantly improved as discussed by the authors.
Abstract: With the help of the radial basis function (RBF) and the Garvey-Kelson relation, the accuracy and predictive power of some global nuclear mass models are significantly improved. The rms deviation between predictions from four models and 2149 known masses falls to $\ensuremath{\sim}$200 keV. The AME95-03 and AME03-Border tests show that the RBF approach is a very useful tool for further improving the reliability of mass models. Simultaneously, the differences from different model predictions for unknown masses are remarkably reduced and the isospin symmetry is better represented when the RBF extrapolation is combined.

96 citations

Journal ArticleDOI
TL;DR: In this paper, the Garvey-Kelson relations (GKRs) were extended to the study of nuclear charge radii, and the GKRs were tested on 455 out of the approximately 800 nuclei whose charge radius is experimentally known.
Abstract: The Garvey-Kelson relations (GKRs) are algebraic expressions originally developed to predict nuclear masses. In this paper we show that the GKRs provide a fruitful framework for the prediction of other physical observables that also display a slowly varying dynamics. Based on this concept, we extend the GKRs to the study of nuclear charge radii. The GKRs are tested on 455 out of the approximately 800 nuclei whose charge radius is experimentally known. We find a rms deviation of 0.01fm between the GK predictions and the experimental values. Predictions are provided for 116 nuclei whose charge radius is presently unknown.

17 citations

Journal ArticleDOI
25 Mar 2013
TL;DR: In this paper, a global nuclear mass formula based on the macroscopic microscopic method, the Skyrme energy-density functional and the isospin symmetry in nuclear physics is introduced.
Abstract: We introduce a global nuclear mass formula which is based on the macroscopic-microscopic method, the Skyrme energy-density functional and the isospin symmetry in nuclear physics. The rms deviation with respect to 2149 known nuclear masses falls to 336 keV, and the rms deviations from 1988 neutron separation energies and α-decay energies of 46 superheavy nuclei are significantly reduced to 286 and 248 keV, respectively. The predictive power of the mass formula for describing new measured masses in GSI and those in AME2011 is excellent. In addition, we introduce an efficient and powerful systematic method, radial basis function approach, for further improving the accuracy and predictive power of global nuclear mass models.

12 citations

Journal ArticleDOI
TL;DR: In this article, the authors used the single-particle spectra in relativistic Hartree-Fock (RHF) theory to extract shell correction energies with the Strutinsky method.
Abstract: The single-particle spectra in relativistic Hartree-Fock (RHF) theory are employed to extract shell correction energies with the Strutinsky method. It is found that proper box sizes ${R}_{\mathrm{box}}$ used in solving the RHF equations are important to extract reliable Strutinsky shell correction energies. An empirical formula to determine ${R}_{\mathrm{box}}$ is proposed by systematic studies on nuclei over a wide range of nuclear charts, including light, heavy, neutron-deficient, and neutron-rich nuclei. Furthermore, the shell correction energies of Ca, Pb, and Og isotopes and $N=50$ isotones are calculated with proper ${R}_{\mathrm{box}}$ and their uncertainties due to the uncertainty of ${R}_{\mathrm{box}}$ are investigated as well. It is found that the results extracted by the Strutinsky method provide a reliable evaluation of the nuclear shell structure information, which can be employed to construct a macroscopic-microscopic mass model in the future.

11 citations