M. Moreno Torres

Publications (5)0 Total impact

• Source

  Available from: cea.fr

  Article: Tensor effects in shell evolution using non-relativistic and relativistic mean field

  M Moreno-Torres, M Grasso, H Liang, V De Donno, M Anguiano, N Van Giai
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  ABSTRACT: Tensor effects in shell evolution are studied within the mean-field approach. Particular attention is paid to the analysis of the proton magic gap Z = 8. Hartree-Fock calculations with Skyrme and Gogny interactions are performed where the tensor term has a zero and finite range, respectively. Results obtained with and without the tensor component are compared between them and with the experimental data. To complete this analysis, the tensor effect is also investigated within the relativistic Hartree-Fock model. It turns out that the tensor effect can be easily identified in the evolution of the proton magic gap Z = 8. We suggest to explicitly include the data associated to this gap evolution as new constraints in the fitting procedures when the tensor contribution is taken into account at the mean-field level.
  Journal of Physics Conference Series 02/2011; 267(1):012039.
• Source

  Available from: G. Co

  Article: Low-lying magnetic excitations of doubly-closed-shell nuclei and nucleon-nucleon effective interactions

  V. De Donno, G. Co, C. Maieron, M. Anguiano, A. M. Lallena, M. Moreno Torres
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  ABSTRACT: We have studied the low lying magnetic spectra of 12C, 16O, 40Ca, 48Ca and 208Pb nuclei within the Random Phase Approximation (RPA) theory, finding that the description of low-lying magnetic states of doubly-closed-shell nuclei imposes severe constraints on the spin and tensor terms of the nucleon-nucleon effective interaction. We have first made an investigation by using four phenomenological effective interactions and we have obtained good agreement with the experimental magnetic spectra, and, to a lesser extent, with the electron scattering responses. Then we have made self-consistent RPA calculations to test the validity of the finite-range D1 Gogny interaction. For all the nuclei under study we have found that this interaction inverts the energies of all the magnetic states forming isospin doublets. Comment: 19 pages, 13 figures, 7 tables, accepted for publication in Phys. Rev. C
  04/2009;
• Source

  Available from: G. Co

  Article: Effective nucleon-nucleon interaction and low-lying nuclear magnetic states

  C. Maieron, V. De Donno, G. Co, M. Anguiano, A. M. Lallena, M. Moreno Torres
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  ABSTRACT: We present a calculation of low energy magnetic states of doubly-closed-shell nuclei. Our results have been obtained within the random phase approximation using different nucleon-nucleon interactions, having zero- or finite-range and including a possible contribution in the tensor channel.
  02/2009;
• Source

  Available from: arxiv.org

  Article: Little Higgs models with a light T quark

  R. Barceló, M. Masip, M. Moreno-Torres
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  ABSTRACT: We study little Higgs models based on a SU1(3)×SU2(3) global symmetry and with two scales (the two vacuum expectation values f1,2) substantially different. We show that all the extra vector boson fields present in these models may be much heavier than the vectorlike T quark necessary to cancel top-quark quadratic corrections. In this case the models become an extension of the Standard Model with a light (≈500 GeV)T quark and a scalar Higgs field with a large singlet component. We obtain that the Yukawa and the gauge couplings of the Higgs are smaller than in the standard model, a fact that may reduce significantly the Higgs production rate through glu–glu and WW fusion. The T quark decay into Higgs boson becomes then the dominant Higgs production channel in hadron colliders.
  Nuclear Physics B. 02/2007;
• Article: Tensor effects in shell evolution at Z, N= 8, 20, and 28 using nonrelativistic and relativistic mean-field theory

  M. Moreno-Torres, M. Grasso, H. Liang, V. De Donno, M. Anguiano, N. Van Giai
  [show abstract] [hide abstract]
  ABSTRACT: Tensor effects in shell evolution are studied within the mean-field approach. Particular attention is paid to the analysis of the magic gaps in different regions of the nuclear chart, namely, Z,N=8, 20, and 28. Hartree-Fock calculations with Skyrme and Gogny interactions are performed where the tensor term has a zero and finite range, respectively. Results obtained with and without the tensor component are compared between them and with the experimental data, when available. To complete this analysis, the tensor effect is also investigated within the relativistic Hartree-Fock model, where the exchange of ρ mesons and pions is taken into account. It turns out that the tensor effect in the evolution of the magic gaps can be more easily identified in the cases Z,N=8 and 20, whereas the interpretation of the effect is more complicated for Z or N= 28. Consequently, we indicate the regions defined by the magic numbers 8 and 20 as suitable for fitting the tensor parameters in a mean-field approach: We suggest to include explicitly the data associated to these gap evolutions in the fitting procedures. In general, with the parametrizations used in this work (which have not been fitted on these data), the mean-field results obtained with the tensor contribution do not reproduce the experimental trend, that is, the reduction of the gaps at 8 and 20 that is observed when going toward the drip lines. Since some of the considered nuclei have N=Z, a discussion will be devoted to the interpretation of the experimental data concerning these nuclei and to the Wigner-energy correction.
  Phys. Rev. C. 81(6).