Papers by Ruslan Magana Vsevolodovna
The construction of the interactions in the nuclear structure coming from the first principles is... more The construction of the interactions in the nuclear structure coming from the first principles is something that from the origin of the quantum mechanics is pursuit, but it is not an easy task to be implemented. Developing phenomenological models is important because will help to understand physical processes which can be analyzed systematically in the experimental data available. The knowledge of the internal degrees of freedom is crucial to understand nuclear structure features like collectivity states, single particle states, pairing properties, etc. There are many experiments and a great deal of research toward the study of the nuclei that helps the development of the compression of the nucleus. Research on transfer reactions, charge exchange reactions plays an essential role to improve the nuclear models. This thesis aims to cover the essential aspects of the description of microscopic interacting boson model applied to different types of problems. Such as the calculation of spectroscopic amplitudes in transfer reactions, nuclear matrix elements of double beta decay without neutrinos and double charge exchange reactions. The knowledge of the nuclear structure allows us to explore and study contemporary problems in modern physics.
Two-nucleon transfer reaction in nuclear supersymmetry
Symmetries and Order: Algebraic Methods in Many Body Systems: A symposium in celebration of the career of Professor Francesco Iachello, 2019
The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements ... more The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0), by high-accuracy measurements of the cross sections of Heavy Ion (HI) induced Double Charge Exchange (DCE) reactions. Particular interest is given to the (18 O, 18 Ne) and (20 Ne, 20 O) reactions as tools for + + and-decays, respectively. First evidence about the possibility to get quantitative information about NME from experiments is found for both kind of reactions. In the experiments, performed at INFN-Laboratory Nazionali del Sud (LNS) in Catania, the beams are accelerated by the Superconducting Cyclotron (CS) and the reaction products are detected by the MAGNEX magnetic spectrometer. The measured cross sections are challengingly low, limiting the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. A major upgrade of the LNS facility is foreseen in order to significantly increase the experimental yield, thus making feasible a systematic study of all the cases of interest. Frontiers technologies are going to be developed, to this purpose, for the accelerator and the detection systems. In parallel, advanced theoretical models are developed aiming at extracting the nuclear structure information from the measured cross sections.
The Hamiltonian for an atom of N electrons is built, different approaches are presented to solve ... more The Hamiltonian for an atom of N electrons is built, different approaches are presented to solve it. Variational Hartree-Fock is introduced and explained in detail applied to the Helium atom. El Hamiltoniano para un a ́tomo de N electrones es construido, se presentan difer- entes enfoques para resolverlos. Se introduce el m ́etodo variacional de Hartree-Fock y se explica en detalle el mtodo aplicado al a ́tomo de Helio.
Supersimetria Molecular - Supersimetria en moleculas diatomicas y reacciones de transferencia
Se presenta una aproximacion algebraica para determinar el espectro electronico de moleculas diat... more Se presenta una aproximacion algebraica para determinar el espectro electronico de moleculas diatomicas usando simetrıas dinamicas del algebra U(4) y U(8). Las simetrıas dinamicas rompen la degeneracion de los niveles energeticos pero no cambian las funciones de onda. Se introduce el concepto de Supersimetrıa Molecular donde un Hamiltoniano que permite dar una descripcion simultanea de los niveles energeticos electronicos, rotacionales y vibraciones en las moleculas LiH, BeH, BH y CH. El modelo vibron el cual describe el espectro rotacional-vibracional de moleculas lineales [1], con el grupo de simetria U(4), se le incluyen los grados de libertad electronicos introduciendo operadores de creacion y aniquilacion que generan un algebra unitaria U(8) que fueron originados desde los estados con los niveles 2s hidrogenoides [2]. La base de los estados se construye por la descomposicion del algebra dinamica que incluye el grupo de rotacion SU(2) que tiene momento angular J, que permite con...
Supersimetria nuclear - Correlaciones entre reacciones de transferencia de nucleones
The basic fundamentals of nuclear physics applied to nuclei with high collective degree are studi... more The basic fundamentals of nuclear physics applied to nuclei with high collective degree are studied. Nuclear transfer reactions in the context of Nuclear Supersymmetry and extensions are presented. The concepts of collective interactions based on groups of symmetries are developed in according to the Theory of Interacting Bosons Model IBM. It was reported the correlations between nucleons transfer reactions for Supersymmetric Nuclei. This work was developed at the National Autonomous University of Mexico in the Faculty of Science in collaboration with the Nuclear Sciences Institute.
International Journal of Modern Physics E, 2012
We study the equation of state (EOS) of nuclear matter as function of density. We expand the ener... more We study the equation of state (EOS) of nuclear matter as function of density. We expand the energy per particle (E/A) of symmetric infinite nuclear matter in powers of the density to take into account 2,3,.. .,N-body forces. New EOS are proposed by fitting ground state properties of nuclear matter (binding energy, compressibility and pressure) and assuming that at high densities a second order phase transition to the Quark Gluon Plasma (QGP) occurs. The latter phase transition is due to symmetry breaking at high density from nuclear matter (locally color white) to the QGP (globally color white). In the simplest implementation of a second order phase transition we calculate the critical exponent δ by using Landau's theory of phase transition. We find δ = 3. Refining the properties of the EOS near the critical point gives δ = 5 in agreement with experimental results. We also discuss some scenarios for the EOS at finite temperatures.
Spectroscopic Amplitudes (SA) in the Interacting Boson Fermion Fermion Model (IBFFM) are necessar... more Spectroscopic Amplitudes (SA) in the Interacting Boson Fermion Fermion Model (IBFFM) are necessary for the computation of 0νββ decays but also for cross sections of heavy-ion reactions, in particular, Double Charge Exchange reactions for the NUMEN collaboration, if one does not want to use the closure limit. We present for the first time: i) the formalism and operators to compute in a general case the spectroscopic amplitudes in the scheme IBFFM from an even-even to odd-odd nuclei, in a way suited to be used in reaction code, i.e., extracting the contribution of each orbital; 2) the odd-odd nuclei as described by the old IBFFM are obtained for the first time with the new implementation of Machine Learning (ML) techniques for fitting the parameters, getting a more realistic description. The one body transition densities for Cd → In and In → Sn are part of the experimental program of the NUMEN experiment, which aims to find constraints on Neutrinoless double beta decay matrix elements.
Generalized F-spin and correlations between one-nucleon transfer reactions
AIP Conference Proceedings, 2012
ABSTRACT In nuclear supersymmetry the spectroscopic properties of even-even, odd-even and oddodd ... more ABSTRACT In nuclear supersymmetry the spectroscopic properties of even-even, odd-even and oddodd nuclei are strongly related to one another. It is shown that these correlations can be derived in terms of SU(3) isoscalar factors by employing the concept of generalized F-spin. As an application we discuss the correlations between one-proton and one-neutron transfer reactions which are relevant for the Pt-Au mass region.
Correlations between nucleon transfer reactions in the context of nuclear supersymmetry
The nuclei belonging to a supersymmetric quartet are described by a single Hamiltonian, and hence... more The nuclei belonging to a supersymmetric quartet are described by a single Hamiltonian, and hence the wave functions, transition and transfer rates are strongly correlated. The correlations between different transfer reactions can be derived in an elegant and explicit way by a generalization of the concept of F-spin. Group theoretically, the generalized F-spin is defined by U (18) ⊃ U (6) ⊗ U (3). Here the U (6) couplings can be described by the three-dimensional index group U (3) then we can get the Clebsch-Gordan cofficients for SU (3), and hence correlations between different transfer reactions can be derived in terms of these isoescalar factors by means of the concept of generalized F-spin
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Papers by Ruslan Magana Vsevolodovna