arXiv subjects

M. J. Ermamatov

Publications and source records attributed to M. J. Ermamatov.

11 recordsLinked to original sources

arXiv2019

Analysis of the one-neutron transfer to $^{16}$O, $^{28}$Si and $^{64}$Ni induced by ($^{18}$O, $^{17}$O) reaction at 84 MeV

Background: Recently, a systematic exploration of two-neutron transfer induced by the ($^{18}$O, $^{16}$O) reaction on different targets has been performed. The high resolution data have been collected at the MAGNEX magnetic spectrometer of the INFN-LNS laboratory in Catania and analyzed with the coupled reaction channel (CRC) approach. The simultaneous and sequential transfers of the two neutrons have been considered under the same theoretical framework without the need of adjustable factors in the calculations. Purpose: A detailed analysis of the one-neutron transfer cross sections is important to study the sequential two-neutron transfer. Here, we examine the ($^{18}$O, $^{17}$O) reaction on $^{16}$O, $^{28}$Si and $^{64}$Ni targets. These even-even nuclei allow for investigation of one-neutron transfer in distinct nuclear shell spaces. Method: The MAGNEX spectrometer was used to measure mass spectra of ejectiles and extract differential cross sections of one-neutron transfer to low-lying states. We adopted the same CRC formalism used in the sequential two-neutron transfer, including relevant channels and using spectroscopic amplitudes obtained from shell model calculations. We also compare with one-step distorted wave Born approximation (DWBA). Results: For the $^{18}$O + $^{16}$O and the $^{18}$O + $^{28}$O systems we used two interactions in the shell model. The experimental angular distributions are reasonably well reproduced by the CRC calculations. In the $^{18}$O + $^{64}$Ni system, we considered only one interaction and the theoretical curve describes the shape and order of magnitude observed in the experimental data. Conclusions: Comparisons between experimental, DWBA and CRC angle-integrated cross sections suggest that excitations before or after the transfer of neutron is relevant in the $^{18}$O + $^{16}$O and $^{18}$O + $^{64}$Ni systems.

nucl-ex↗

arXiv2019

Different seniority states of $^{119-126}$Sn isotopes: shell model description

In the present work available experimental data up to high-spin states of $^{119-126}$Sn isotopes with different seniority ($v$), including $v$ = 4, 5, 6, and 7 have been interpreted with shell model, by performing full-fledged shell model calculations in the 50-82 valence shell composed of $1g_{7/2}$, $2d_{5/2}$, $1h_{11/2}$, $3s_{1/2}$, and $2d_{3/2}$ orbitals. The results have been compared with the available experimental data. These states are described in terms of broken neutron pairs occupying the $h_{11/2}$ orbital. Possible configurations of seniority isomers in these nuclei are discussed. The breaking of three neutron pairs have been responsible for generating high-spin states. The isomeric states $5^-$, $7^-$, $10^+$ and $15^-$ of even Sn isotopes, and isomeric states $19/2^+$, $23/2^+$, $27/2^-$ and $35/2^+$ of odd Sn isotopes, are described in terms of different seniority. For even-Sn isotopes, the isomeric states $5^-$, $7^-$, and $10^+$ are due to seniority $v$ = 2; the isomeric state $15^-$ is due to seniority $v$ = 4, and in the case of odd-Sn isotopes, the isomeric states $19/2^+$, $23/2^+$, and $27/2^-$ are due to seniority $v$ = 3, and the isomeric state $35/2^+$ in $^{123}$Sn is due to seniority $v$ = 5. These are maximally-aligned spin, which involve successive pair breakings in the $ν(h_{11/2})$ orbit.

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arXiv2017

$^{35,37,39}$S isotopes in $sd-pf$ space : Shell-model interpretation

The structure of $^{35,37,39}$S isotopes is described by performing comprehensive shell model calculations with SDPF-U and SDPFMW interactions. Protons and neutrons are restricted to the $sd$-shell for $N < 20$, neutrons start to fill the $pf$-shell for $N > 20$. Natural parity states are described by only in-shell mixing, unnatural parity states with 1p-1h inter-shell neutron excitations. With SDPF-U interaction, reported are the results for natural parity states only because this interaction is not suitable for cross shell excitations. Calculated energy levels, electromagnetic properties and spectroscopic factors are in good agreement with the recently available experimental data.

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arXiv2016

High-spin structure of $^{87}$Sr and $^{87}$Zr nuclei : shell model interpretation

In the present work we report a comprehensive analysis of shell model results for high-spin states of $^{87}$Sr and $^{87}$Zr for recently available experimental data within the full $f_{5/2}pg_{9/2}$ model space using JUN45 and jj44b effective interactions developed for this model space. In this work we have compared the energy levels, electromagnetic transition probabilities, quadrupole and magnetic moments with available experimental data. We have confirmed structure of high-spin states of these two nuclei which were tentatively assigned in the recent experimental work. In the case of $^{87}$Sr, for positive parity states up to $\sim$ 7.5 MeV, both interactions predict very good agreement with experimental data, while negative parity states are slightly suppressed in jj44b calculation.For the $^{87}$Zr nucleus, the jj44b interaction predicts higher energies for the negative parity states beyond $J \geq 27/2^{-}$. The configuration, which have one hole in $νg_{9/2}$ orbital, is responsible for generating the states in $^{87}$Sr. In the case of $^{87}$Zr, low-lying positive parity states come with the configuration having three holes in the $νg_{9/2}$, while the odd-parity states have configuration $ν(f_{5/2}^{-1}g_{9/2}^{-2})$.

nucl-th↗

arXiv2015

Analysis of proton and neutron pair breakings: High-spin structures of $^{124-127}$Te isotopes

In the present work recently available experimental data for high-spin states of four nuclei, $^{124}_{\ 52}$Te, $^{125}_{\ 52}$Te, $^{126}_{\ 52}$Te, and $^{127}_{\ 52}$Te have been interpreted using state-of-the-art shell model calculations. The calculations have been performed in the $50-82$ valence shell composed of $1g_{7/2}$, $2d_{5/2}$, $1h_{11/2}$, $3s_{1/2}$, and $2d_{3/2}$ orbitals. We have compared our results with the available experimental data for excitation energies and transition probabilities, including high-spin states. The results are in reasonable agreement with the available experimental data. The wave functions, particularly, the specific proton and neutron configurations which are involved to generate the angular momentum along the yrast lines are discussed. We have also estimated overall contribution of three-body forces in the energy level shifting. Finally, results with modified effective interaction are also reported.

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arXiv2014

High-spin structures of $^{86,87,88,89}$Y: a shell model interpretation

In this work nuclear structure properties of $^{86,87,88,89}$Y isotopes have been investigated using large-scale shell-model calculations within the full $f_{5/2}pg_{9/2}$ model space. The calculations have been performed with JUN45 and jj44b effective interactions that have been proposed for use in the $f_{5/2}$, $p_{3/2}$, $p_{1/2}$, $g_{9/2}$ model space for both protons and neutrons. Reasonable agreement between experimental and calculated values are obtained. This work will add more information to previous study by projected shell model [Eur. Phys. J. A 48, 138 (2012)] where full-fledged shell model calculations proposed for these nuclei.

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arXiv2013

Comparison of shell model results for even-even Se isotopes

Comprehensive set of shell model calculations for $^{78-84}$Se isotopes have been performed with recently derived interactions, namely JUN45 and jj44b for ${f_{5/2}pg_{9/2}}$ space. To study the importance of the proton excitations across Z=28 shell in this region mentioned by Cheal {\it et al.} [Phys. Rev. Lett. {\bf104}, 252502 (2010)], calculation for ${fpg_{9/2}}$ valence space using an ${fpg}$ effective interaction with $^{48}$Ca as core and imposing a truncation has also been performed. Comparison of the calculations with experimental data show that the predicted results of jj44b interaction are in good agreement with experimental data.

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arXiv2013

High-spin structures of $^{136}_{54}$Xe, $^{137}_{55}$Cs, $^{138}_{56}$Ba, $^{139}_{57}$La, and $^{140}_{58}$Ce : A shell model description

In the present work recently available experimental data [A. Astier et al, Phys. Rev. C 85, 064316 (2012)] for high-spin states of five N=82 isotones, $^{136}_{54}$Xe, $^{137}_{55}$Cs, $^{138}_{56}$Ba, $^{139}_{57}$La, and $^{140}_{58}$Ce have been interpreted with state-of-the-art shell model calculations. The calculations have been performed in the 50-82 valence shell composed of $1g_{7/2}$, $2d_{5/2}$, $1h_{11/2}$, $3s_{1/2}$, and $2d_{3/2}$ orbitals. We have compared our results with the available experimental data for excitation energies including high-spin states, occupancy numbers and transition probabilities. As expected the structure of these isotones are due to proton excitations across Z=50 shell. The structure of the positive-parity states are mainly from $(πg_{7/2}πd_{5/2})^n$ and $(πg_{7/2}πd_{5/2})^{n-2}(πh_{11/2})^2$ configurations, while the negative-parity states have $(πg_{7/2}πd_{5/2})^{n}(πh_{11/2})^1$ configuration. Additionally, for the $^{136}_{54}$Xe, $^{137}_{55}$Cs and $^{138}_{56}$Ba isotones the excitation of the neutrons across N=82 gap is important.

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arXiv2012

Structure of odd Ge isotopes with $40 < N < 50$

We have interpreted recently measured experimental data of $^{77}$Ge, and also for $^{73,75,79,81}$Ge isotopes in terms of state-of-the-art shell model calculations. Excitation energies, B(2) values, quadrupole moments and magnetic moments are compared with experimental data when available. The calculations have been performed with the recently derived interactions, namely with JUN45 and jj44b for ${f_{5/2}pg_{9/2}}$ space. We have also performed calculation for ${fpg_{9/2}}$ valence space using an ${fpg}$ effective interaction with $^{48}$Ca core and imposing a truncation to study the importance of the proton excitations across the Z=28 shell in this region. The predicted results of jj44b interaction are in good agreement with experimental data.

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arXiv2006

Rotational Analog of the Hall Effect: Coriolis Contribution to Electric Current

A galvanogyroscopic effect which is the rotational analog of the gravitomagnetic Hall effect has been proposed. As a consequence of Ohm's law in the rotating frame, the effect of the Coriolis force on the conduction current is predicted to give rise to an azimuthal potential difference $V_{gg}$ about $10^{-3}V$ in a spinning rotor carrying radial electric current $i_r$. The potential difference developed by the galvanogyroscopic effect is proportional both to angular velocity ${\mathbf Ω}$ and to the electric current.

cond-mat.other↗

arXiv2006

Electrical Conductivity in General Relativity

The general relativistic kinetic theory including the effect of a stationary gravitational field is applied to the electromagnetic transport processes in conductors. Then it is applied to derive the general relativistic Ohm's law where the gravitomagnetic terms are incorporated. The total electric charge quantity and charge distribution inside conductors carrying conduction current in some relativistic cases are considered. The general relativistic Ohm's law is applied to predict new gravitomagnetic and gyroscopic effects which can, in principle, be used to detect the Lense-Thirring and rotational fields.

gr-qc↗