There are only a few works using the boson approach to describe the intersection of the collective band and the band built on a two-quasiparticle mode. The first of these was the work of Gelberg and Zemel [1] based on IBM1. In it, the Hamiltonian term responsible for the interaction of the collective and non-collective bands was replaced by a constant and did not depend on either the spin $J$...
$\qquad$ ะะทะพัะพะฟั $^{182,184}\rm{W}$ ะผะฝะพะณะพะบัะฐัะฝะพ ะธะทััะฐะปะธัั ะฒ ัะฐัะฟะฐะดะต $^{182,184}\rm{Ta}$ ะธ ะผะฝะพะณะพัะธัะปะตะฝะฝัั ัะดะตัะฝัั ัะตะฐะบัะธัั [1-5]. ะะฐะธะฑะพะปะตะต ะฟะพะปะฝัะต ัะตะทัะปััะฐัั ะฟะพ ััะธะผ ัะดัะฐะผ ะฟัะตะดััะฐะฒะปะตะฝั ะฒ ัะฐะฑะพัะต [1,2]. ะญะฝะตัะณะธะธ ะบะพะปะปะตะบัะธะฒะฝะธั ััะพะฒะฝะตะน ะฝะธะทะบะพะปะตะถะฐัะธั ะฟะพะปะพั ะฑะปะธะทะบะธ ะบ ัะฐัััะธัะฐะฝะฝัะผ ะฟะพ ัะฒะตัั ัะตะบััะตะน ะผะพะดะตะปะธ [6].
$\qquad$ ะญะบัะฟะตัะธะผะตะฝัะฐะปัะฝัะต ะดะฐะฝะฝัะต ัะฝะตัะณะธะธ, ะฒะตัะพััะฝะพััะตะน ะฒะฝัััะธะฟะพะปะพัะฝัั ะธ ะผะตะถะฟะพะปะพัะฝัั ...
Calculations of the structure of the low-lying states of nuclei with $Z = 97โ109$ play an important role in understanding the properties of nuclei belonging to the new region of the nuclide chart, which is available
now for experimental study. We calculated quasiparticle-phonon structure and the reduced $\gamma$-transition probabilities for the excitedstates with excitation energies below 1...
A system of two identical spinless fermions on the two-dimensional lattice is studied [1] under the assumption that the first and second nearest-neighboring-site interactions between the fermions are only nontrivial and that these interactions are of magnitudes $\lambda$ and $\mu$, respectively. A partition of the $(\lambda,\mu)$ plane is established such that, in each its connected component,...
An application of neural networks for solving quantum mechanical problems has been suggested in [1,2]. Many improvements, including an adaptation of deep neural network techniques [3], have been proposed since. Development of a new computational technology which could lift the curse of dimensionality, however, has not yet been completed, although some steps in this direction have already been...
Induced dipole interaction in scattering of positrons and electrons off light atomic target
V.A. Gradusov1, S.L. Yakovlev1
1St Petersburg State University, St Petersburg, Russia;
E-mail: v.gradusov@spbu.ru, s.yakovlev@spbu.ru
Scattering of a charged particle with a two-particle target system which is bound by the attractive Coulomb interaction is considered. Although, the leading...
Singly ionizing ion-atom collisions are investigated theoretically. A parabolic quasi-Sturmian approach is applied to the single ionization of helium atom by intermediate- and high-energy protons. The fully differential cross sections (FDCSs) are calculated for 1 MeV and 75 keV protons.
The alignment and orientation of the linear molecule by the two-color trapezoidal laser pulses were theoretically investigated. The use of the trapezoidal shape of a laser pulse enhances the maximum alignment degree for the same intensity and duration comparing to the Gaussian laser pulse. Influence of pulse duration on the maximum degrees of molecule alignment and orientation was...
The model of the one-dimensional impenetrable particles with interactions via the boundary conditions is considered. This model, besides its relation to the three-body problem [1-3],
describes also the wave diffraction problem for
the impedance wedge [4]. Previously, an exact solution was obtained by means of the Maluzhinetz-Sommerfeld transformation [4,2,3]. In the present report it was...
The SS-HORSEโNCSM method [1] is generalized to the case of democratic decay into an odd number of fragments. This method is applied to the search for resonances in three-neutron system (trineutron) using ab initio No-Core Shell Model [2] calculations with realistic nucleon-nucleon potentials [3-5].
We predict two overlapping trineutron resonances with spin-parities $3/2^โ$ and $1/2^โ$ which...
Recently we have suggested a new method for calculating resonance parameters in multi-channel and three-body systems, using the formalism of the spectral shift and spectral density functions [1]. The method is based on the possibility of reconstructing the spectral and integrated density of states from discretized spectra of the total and asymptotic Hamiltonians found within the variational...
High momentum components of wave functions and two-nucleon short-range correlations (SRC) for the lightest nuclei with A=2 and 3 are studied within the dibaryon model for 2N and 3N forces [1]. This model accounts for a possibility of an intermediate six-quark (dibaryon) state formation in two-nucleon system at short distances. We evaluate the SRC probability for the deuteron and calculate the...
Searches for bound or resonant state in the system of 4 neutrons (tetraneutron) have been started more than half a century ago. Theory completely excludes the bound tetraneutron. Numerous theoretical studies allowing for the continuum with modern NN interactions exclude also low-lying tetraneutron resonance narrow enough to be detected experimentally. A notable exception is the predictions of...
Being associated with breathing modes of high-energy nuclear excitations,the Isoscalar Giant Monopole Resonance (ISGMR) is the object of permanent experimental and theoretical studies [1, 2]. In studies of Ref. [2], the detailed theoretical description of ISGMR (together with L=1,2,3) isoscalar GRs) in medium-heavy closed-shell nuclei have been proposed within the semi-microscopic...
A comprehensive analysis of the isoscalar giant monopole resonance (ISGMR) has long been a subject of extensive theoretical and experimental research [1,2]. The ISGMR properties are presently an important problem not only from the nuclear structure point of view [2,3] but also because of the special role they play in many astrophysical processes such as prompt supernova explosions [4] and the...
I. N. Borzov 1), 2)*, S. V. Tolokonnikov 1), 3)
1) National Research Center โKurchatov Institute", Moscow, Russia.
2) Bogolubov Laboratory of Theoretical Physics, JINR, Dubna, Russia.
3) Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia.
The strength functions of charge exchange spin-dipole (SD) excitations are calculated in the continuum...
The probability of the $\beta$-transition is proportional to the product of the lepton part described by the Fermi function $f( \textit{Q}_{\beta} - E)$ and the nucleon part described by the $\beta$-decay strength function $S_{\beta}(\textit{E})$ . Until recently, experimental investigations of the $S_{\beta}(\textit{E})$ structure were carried out using total absorption gamma-ray...
Optical spectroscopy is able to measure subtle shifts in the energy of the atomic electron levels, arising from changes in the charge distribution of the nucleus [1]. For a given isotopic chain, this effect, known as the isotope shift (IS), arises due to changes in the nuclear mass and size. From this, the change in mean-square charge radius ($\delta\langle r^2\rangle$) can be extracted in a...
Nuclei in the "lead region" of the nuclide chart ($Z$ close to 82) are of particular importance for nuclear physics. Nuclides in the vicinity of neutron mid-shell $N$ = 104 exhibits striking effects such as shape coexistence, shape staggering $etc$. The heavier isotopes ($N$ > 126) are also of great interest. One of the reasons is so-called "shell effect" in charge radii [1]. This effect...
Nuclear electromagnetic moments and radii near N = 126 neutron shell
I.N. Borzov, 1, 2, โ and S. V. Tolokonnikov 1, 3, โ
1) National Research CentreโKurchatov Instituteโ, Moscow, Russia
2) Bogolubov Laboratory of Theoretical Physics, JINR, Dubna, Russia
3) Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
Charge radii of Tl, Pb and Bi...
The evolution of neutron single-particle characteristics of isotones with N = 14, 16 was studied in the dispersive optical model /1/ in Z region from 7 to 20. The calculation was performed with the parameters both extrapolated in accordance with the global parameters KD (KDUQ) /2, 3/ and with the diffuseness parameter $a_{HF}$ depending on the neutron excess. With an increase in the neutron...
The radial wave functions and the energies of the protons and neutrons in the same states of the corresponding mirror nuclei differ due to the Coulomb interaction. Mirror energy difference (MED) between the energy of protons and neutrons in these states depend on angular momentum (the Thomas-Ehrman effect $[$1]). The single-particle structure of the mirror nuclei $^{52}$Ni-$^{52}$Cr,...
This work examines the excitation of anomalous parity levels 1^+ in some light and medium nuclei with filled or partially filled shells. Nuclei {12}^C, {16}^O, {18}^O, {28}^Si, {48}^Ca are considered. The wave functions of excited states were calculated within the framework of the shell model using the NuShellX program [1]. Within the framework of this program, the calculation of excited...
The scissors mode is investigated in the actinide region, including even-even superheavy nuclei up to $^{256}$No, within the Time Dependent Hartree-Fock-Bogoliubov (TDHFB) approach. The solution of TDHFB equations by the Wigner Function Moments (WFM) method predicts a splitting of the scissors mode into three intermingled branches due to spin degrees of freedom [1]. Both the calculated energy...
In a series of papers [1], a generalization of the theory of finite fermi systems (TFFS) was developed within the framework of the Green's function method to consistently account for complex configurations with phonons. However, quantitative estimates of the effects obtained there were not carried out due to the large quantitative difficulties. It seems that these difficulties can be...
The formation of superconducting pair correlations
between like nucleons in the ground state of spherical
even-even nuclei is considered within a special Bogoliubov
transformation.
The influence of the monopole pairing interaction on
the energy of single-particle states is taken into account.
It is shown that the emergence of pair correlations
depends on the particle...
ะะพะบะฐะปัะฝัะต ะผะฐััะพะฒัะต ัะพะพัะฝะพัะตะฝะธั ะะฐัะฒะธ-ะะตะปัะพะฝะฐ GKT ะธ GKL, ะฟัะตะดะปะพะถะตะฝะฝัะต ะฒ ัะฐะฑะพัะต [1], ัะธัะพะบะพ ะธัะฟะพะปัะทะพะฒะฐะปะธัั ะดะปั ะธะทััะตะฝะธั ัะฒะพะนััะฒ ัะดะตัะฝะพะณะพ ะฒะทะฐะธะผะพะดะตะนััะฒะธั, ะฝัะบะปะพะฝะฝัั ะบะพััะตะปััะธะน, ะฐ ัะฐะบะถะต ะดะปั ะฟัะตะดัะบะฐะทะฐะฝะธั ะผะฐัั ะฝะตะธะทะฒะตััะฝัั ัะดะตั. GKT ะธ GKL ะฟัะตะดััะฐะฒะปััั ัะพะฑะพะน ะฟัะพัััะต ะฐัะธัะผะตัะธัะตัะบะธะต ัะพะพัะฝะพัะตะฝะธั ะผะตะถะดั ะผะฐััะฐะผะธ 6 ัะพัะตะดะฝะธั ัะดะตั, ะฒัะฟะพะปะฝัััะธะตัั ั ัะพัะฝะพัััั ะพะบะพะปะพ 200-300 ะบัะ ะฝะฐ ะฒัะตะน ัะพะฒะพะบัะฟะฝะพััะธ ะธะทะผะตัะตะฝะฝัั ะผะฐัั...
Wigner Function Moments method is applied to solve Time Dependent Hartree-Fock-Bogoliubov equations. The dynamical equations for the second rank irreducible tensors are derived. Their solution for $^{164}$Dy produces fourteen energy levels: ten high lying ones with $E>10$ MeV (including isoscalar and isovector Giant Quadrupole Resonances) and four low lying $K^{\pi}=1^+$ ones with $E<4$ MeV....
Various relationships between the characteristics of low-lying
states of even-even nuclei, including the first excited 1- state, are
derived and discussed. Checking them
can become part of the program of experimental research on the created
at the National Center for Physics and Mathematics Compton Source of
monochromatic photons.
At FLNR JINR experiments are carried out to investigate the radioactive decay properties (ฮฑ, ฮฒ, ฮณ spectroscopy) and the cross section measurements of transfermium elements synthesised in the fusion-evaporation reaction of an accelerated heavy ion beam with target nuclei using the kinematic separator SHELS [1,2] at the cyclotron U-400 and the gas-filled separator GRAND, located at the Factory...
The exact calculation of half-lives in spontaneous fission remains an open problem in nuclear physics. In this work, a new systematics of half-lives in spontaneous fission was proposed. For nuclei with the same value of neutron excess (isospin) and charge numbers $90\leq Z \leq 102$, a linear correlation was found between the decimal logarithm of the half-life of spontaneous fission and the...
In the framework of the semi-empirical quark model of nuclear structure that is based on the quark model of the nucleon, the Strongly Correlated Quark Model (SCQM) we construct nuclei from light to heavy ones, including halo nuclei. Nucleons inside nuclei are bound due to junctions of SU(3) color fields of quarks [1]. According to SCQM, arrangement of nucleons within nuclei reveals the...
In present work model of effective triaxiality of even-even nuclei with quadrupole and octupole deformation is developed. To solve for radial part the Schrodinger equation the Davidson potential was used. The alternating parity energy spectrum and wave functions of Schrodinger equation was obtained. The contribution of quantity $e_ฮฝ$ - eigenvalues for angular part of polar coordinate taken...
Computational scheme and solver of the finite element method for solving elliptic multidimensional boundary value problems with variable coefficients given as in analytical, as in tabular form describing collective models of atomic nuclei implemented in Mathematica and C++ are presented.
Benchmark calculations of the spectrum, quadrupole momentum and electric B(2E) transitions of generalized...
