Conveners
Nuclear structure: theory and experiment
- Dmitri Eremenko ()
Nuclear structure: theory and experiment
- Dmitri Eremenko ()
Nuclear structure: theory and experiment
- Alexander Mazur (Pacific National University)
Nuclear structure: theory and experiment
- Alexander Mazur (Pacific National University)
Nuclear structure: theory and experiment: NS3
- Valentin Nesterenko (BLTP, Joint Institute for Nuclear Research)
Nuclear structure: theory and experiment: NS3
- Valentin Nesterenko (BLTP, Joint Institute for Nuclear Research)
Nuclear structure: theory and experiment: NS1
- Igor Izosimov (JINR)
Nuclear structure: theory and experiment: Few body
- Alexander K. Motovilov (BLTP, JINR, Dubna)
Nuclear structure: theory and experiment: Few body
- Alexander K. Motovilov (BLTP, JINR, Dubna)
Nuclear structure: theory and experiment: NS1
- Igor Izosimov (JINR)
Nuclear structure: theory and experiment: Few body
- Vladimir Melezhik (BLTP JINR)
Nuclear structure: theory and experiment: NS1
- Alexander Mazur (Pacific National University)
Nuclear structure: theory and experiment: NS1
- Alexander Mazur (Pacific National University)
We present results of the first experiments aimed at the synthesis of Mc isotopes in the 243Am+48Ca reaction performed at the new gas-filled separator DGFRS-2 on-line to the new cyclotron DC280 at the SHE Factory at JINR. One hundred-ten new decay chains of 288Mc, four new decay chains of 287Mc and ten chains assigned to 289Mc were detected. The α-decay of 268Db with an energy of 7.6-8.0 MeV,...
At FLNR JINR, experiments are aimed to investigate the radioactive decay properties ($\alpha$, $\beta$, $\gamma$-spectroscopy) and the cross sections measurements of transfermium elements, synthesized in complete fusion reaction of accelerated heavy ion beam with target nuclei, with subsequent evaporation of several light particles at the kinematic separator SHELS [1,2]. A number of...
For more than 20 years, experiments on the synthesis and study of the properties of radioactive decay of short-lived isotopes of transuranic elements have been conducted at the Flerov Nuclear Reactions Laboratory of JINR. The reactions of complete fusion of accelerated multicharged ions with target nuclei heavier than lead were mainly used. In these experiments, experimental installations with...
The spontaneous fission is one of the decay channel on a par with α- and β+-decays for heavy and super-heavy isotopes (Z > 100). There are no established models that could describe all details of spontaneous process well yet. Therefore, experimental studies of such processes are high-interesting and important.
The combination of relatively high formation cross-section in complete fusion...
This work presents the results of the experiments performed at the FLNR, JINR Superheavy Element Factory (SHE Factory). The experiments were carried out on the basis of the new cyclotron DC-280 with an intensity of accelerated particles of up to 10 pµA [1] and gas filled separator DGFRS-2 [2] and were aimed at study of the $^{242}$Pu+$^{48}$Ca and $^{238}$U+$^{48}$Ca reactions. The main goal...
$^{13}$C is a good example of a “normal” nucleus that is well described in the framework of the shell model. Its level scheme is reliably determined up to excitation energies ~ 10 MeV.
However, some open questions remain regarding the structure of low-lying $^{13}$C states. This leads to increased attention to $^{13}$C so far.
In [1] a hypothesis was put forward about a new type of symmetry...
The size of a nucleus defined by the radius of its nucleon (proton and neutron) density distribution and the proton charge distribution is one of the most fundamental and important nuclear characteristics. Nuclear radius determines the basic properties of nuclei and is a consequence of the fundamental features of the strong interaction.
The development of methods of measuring the radii of...
The results of measurements of the angular distributions of deuterons in the 45Sc(3He, d)46Ti reaction are presented, from which the cross sections for population of the ground and excited states in the 46Ti nucleus were determined [1]. The energy of the bombarding 3He particles was 29 MeV.
The measured angular distributions for the excited states in the 46Ti nuclei are compared with the...
Level structure of heavy helium isotope $^8$He is studied in the reactions of stopped pion absorption $^9$Be($\pi^-,p$)X, $^{10}$B($\pi^-,pp$)X, $^{11}$B($\pi^-,pd$)X, $^{12}$C($\pi^-,p^3$Нe)X, $^{14}$C($\pi^-,d^4$Нe)X, $^{14}$C($\pi^-,t^3$Нe)X. The experiment was carried out at the LANL with a two-arm semiconductor spectrometer. The ground and excited states have been observed. The...
Experimental manifestation of the strong nuclear interaction in the optical spectra of solids
V.G. Plekhanov
Fonoriton Sci. Lab., Garon Ltd, Tallinn 11413, Estonia, vgplekhanov@gmail.com
The primary task amongst other nuclear physics fundamental tasks is experimental measuring of nuclear force interacting between nucleons (protons and neutrons) and their dependence on...
Isovector and isoscalar spin-flip excitations in even-even sd-shell nuclei excited by inelastic proton scattering were considered in [1]. Recently M1 excitations in sd-shell were also analyzed in [2]. In [2] only strongest excitations of $^{28}$Si were discussed. Shell model predicts for $^{28}$Si a few of 1$^+$ states with excitation energy lower than 20 MeV. Nearly all of these states can...
In order to follow relative yields of 209Bi(γ,xn) reactions, samples of natural bismuth were exposed in LINAC 200 bremsstrahlung beam at several different energies (40 MeV, 60 MeV, 80 MeV and 100 MeV). Activities of eight obtained products of photonuclear reactions with different neutron multiplicity, from (γ,2n) to (γ,9n) were detected. Relative yields were calculated for all of them. All...
GRAND is a Gas-filled Recoil Analyzer and Nuclei Detector (see Fig.1), which created for experiments on the synthesis of super heavy elements. Facility is installed at 4th beam line of the cyclotron DC-280[2] in the SHE Factory at FLNR [1]. This separator has the scheme QvDhQhQvD. Helium with a pressure of P=0.7-1.5 mBa is used as the gas. The ion optical calculations for the complete system...
Direct one-nucleon decay of giant resonances (GRs) is the subject of permanent (but not-too-intensive) experimental and theoretical studies. They allow one to get information on GR structure and decay mechanisms. Decay probabilities are usually deduced from a common analysis of cross sections of direct inclusive and “decay” reactions. In Ref. [1], direct one-neutron decay of Isoscalar Giant...
The 229mTh isomeric state with an energy of about 8 eV is formed in 2% of the cases of 233U α-decay (see ref. [1] and references therein). For neutral 229mTh atoms, the main decay channel is nonradiative – it is either electronic conversion or decay via an electronic bridge. An estimate of the probability of a decay with photon emission γTh gives a half-life T1/2 ≈ 2 h and is much smaller than...
The overwhelming majority of the experimental atomic-level widths in thorium (see, e.g., the compilation [1]) were determined by the X-ray emission spectroscopy and only several N-subshell values were obtained by the XPS method. There are no available relevant experimental data determined by another methods. Therefore, we used suitable conversion electron lines of the 9.2, 15.1 and 24.3 keV...
The 9.2, 15.1, and 24.3 keV nuclear transitions in 227Th were studied in the --decay of 227Ac by means of the internal conversion electron spectroscopy (ICES) using the combined electrostatic electron spectrometer [1] and the computer code SOFIE (see, e.g., Ref. [2]) to clarify the spin-parity assignment of the ground state and the two lowest excited states in 227Th. Results obtained were...
Currently, one of the topical research areas in the field of the nuclear structure experimental and theoretical studies is the experimental and theoretical study of the negative parity states in the actinide nuclei [1]. In the 238U nucleus, rotational bands based on the ground and octupole vibrational states are known. Most of the experimental data were obtained using Coulomb excitation [2]...
Analysis of the available experimental data obtained for the reactions , and at the nucleus, shows that almost all excited energy levels up to 2.0 MeV may be assumed to be uncovered [1]. The experimental data indicate the presence of a deviation from the Alaga rule. In particular, forbidden transitions from states of the band are observed.
In [2, 3], within the framework of the...
The generalized equation for the main notion of the self-consistent theory of finite Fermi-systems (TFFS) [1,2] effective field ( vertex) $\tilde V$, which describes nuclear polarizability, has been derived for the case of consistent accounting for phonon coupling (PC) in the energy region of pygmy-and giant resonances (GDR , GMR) in magic nuclei [3,4]:
Figure 1. F – effective...
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...
Properties of giant resonances (GRs) associated with high-energy particle-hole (p-h) excitations in medium-heavy nuclei are described by a number of characteristics and parameters. Main characteristics include the energy-averaged strength function and “projected” transition density, both related to an appropriated single-particle external field (probing operator), and strength functions of...
Deviations of nuclear properties from shell model predictions are very sensitive to value of nuclear surface tension [1]. Although the quantitative estimation of these deviations is not yet possible, a level of deviation is indicated by the values of the nuclear surface tension coefficient σ. These deviations are minimal for nuclei with high values of the coefficient σ. The nuclei of iron...
The calculation of the surface tension coefficients σ of even-even nuclei [1] showed the decisive role of shell effects in the formation of the value of σ. The addition of neutron pairs to the "magic" nucleus leads, as a rule, to a decrease in σ (Fig. 1). Low values of σ change little upon addition of neutron pairs until a neutron-closed subshell is obtained, when the surface tension sharply...
A new kind of atomic nuclei, local magic nuclei (l.m.n.), have been discovered recently [1]. We present in this report a current state of relevant research.
L.m.n. have the same observable features as traditional magic nuclei, i.e. elevated energies of the first 2+ excitations, increased nucleon separation energies, and so on. However, unlike the traditional magic nuclei, l.m.n. do not have...
More pronounced increase in the neutron surface diffuseness with increasing of neutron excess is expected for the nuclei far from the β-stability valley [1,2] in comparison with the stable ones. Earlier, the halo and giant halo were predicted for the Zr isotopes near the neutron drip line by the relativistic Hartree-Bogoliubov theory [3]. We studied the halo structure of these isotopes within...
We propose semi-empirical quark model of nuclear structure that is based on the quark model of nucleon structure, Strongly Correlated Quark Model (SCQM). Nuclei are constructed due to junctions of SU(3) color fields of quarks of neighbor nucleons [1]. According to SCQM, arrangement of nucleons within nuclei reveals the emergence of the face-centered cubic (FCC) symmetry [2]. The model of...
As it was shown in [1,2], the mass surface M of odd deformed atomic nuclei with 150 < A < 190 in the vicinity of a given number of protons can be described with good accuracy by the sum of two terms:
μ–a Tailor series expansion up to the second order by degrees of deviation of the number of nucleons from the given values:
PN (PZ) – neutron (proton) pairing energy, depending on the state of...
Oscillator basis is widely used in nuclear structure studies, e. g., within ab initio No-Core Shell Model (NCSM) [1]. A problem faced by the NCSM calculations is an exponential grows of the many-body basis dimension and of the number of non-zero Hamiltonian matrix elements which restricts the accuracy of the results and the NCSM applicability to heavier nuclei. This difficulty can be...
Theoretical study of antihydrogen formation reactions in the three body e-e+p̅ system via Faddeev-Merkuriev
equations in total orbital momentum representation
V.A. Gradusov1, V.A. Roudnev1, E.A. Yarevsky1, S.L. Yakovlev1
1St Petersburg State University, St Petersburg, Russia;
E-mail: v.gradusov@spbu.ru
We present the results of calculations of low-energy reaction in the three body...
The modern theory of the structure of light nuclei is actively developing due to the introduction of ab initio (from first principles) methods of describing nuclear systems. An essential place among such methods is occupied by various versions of No-Core Shell Model (NCSM) (see, for example, [1]) that uses huge multi-nucleon bases and realistic NN potentials to describe the interaction of...
By a quantum speed limit one usually understands an estimate on how fast a quantum system can evolve between two distinguishable states. The most known quantum speed limit is given in the form of the celebrated Mandelstam-Tamm inequality that bounds the speed of the evolution of a state in terms of its energy dispersion. In contrast to the basic Mandelstam-Tamm inequality, we are concerned...
The problem of describing the size parameters (matter, charge, neutron radii) of nuclei in an ab initio approach attracts a wide range of researchers. The size parameters of exotic nuclei, in particular, the size of halo (neuron or proton), have the greatest physical significance.
In the present work, for these purposes, one of the most reliable and justified ab initio approaches, No-Core...
Solving scattering problems in L2 bases is a perspective way which allows to treat problems for continuum nearly on the same footing as the discrete spectrum ones. Recently we have suggested a new technique for reconstructing scattering amplitude directly from discretized spectra of the total and asymptotic Hamiltonians found with variational method [1]. It was shown also how the discretized...
We review the recent results obtained within the dibaryon model for NN interaction [1-4]. The model takes into account the formation of the intermediate six-quark (dibaryon) state in each partial wave. The respective mechanism leads to an energy-dependent term in the interaction which reflects the coupling with the internal non-nucleonic channel.
The substantial progress in the description...
We have proposed the SS-HORSE approach [1] which makes it possible to calculate scattering phase shifts and S-matrix based on variational results in the oscillator basis. Within SS-HORSE, one can locate the S-matrix poles to obtain resonance parameters [1] and improve the description of bound states [2].
We discuss the results of our recent applications of the SS-HORSE approach combined with...
CONTRIBUTION OF INDUCED DIPOLE INTERACTION TO THE ASYMPTOTIC BEHAVIOR OF WAVE FUNCTION COMPONENTS FOR THE SCATTERING IN THREE BODY COULOMB SYSTEMS
V.A. Gradusov1, S.L. Yakovlev1
1St Petersburg State University, St Petersburg, Russia;
E-mail: s.yakovlev@spbu.ru
We consider the scattering of a charged particle with a two-particle target system which is bound by the attractive Coulomb...
The BECQUEREL experiment is aimed at solving topical problems in nuclear cluster physics [1]. Due to its unique sensitivity and spatial resolution the used method of nuclear track emulsion (NTE) makes it possible, to study in a unified approach multiple final states arising in the dissociation of relativistic nuclei. The focus is a concept of α-particle Bose-Einstein condensate ($\alpha$BEC) -...
We study the discrete spectrum of the two-particle Schrodinger operator depending on the quasi-momentum associated to the Bose-Hubbard Hamiltonian of a system of two identical bosons interacting on one site and nearest-neighbor sites in the two-dimensional lattice with arbitrary interaction magnitudes. We completely describe the spectrum of Schrodinger operator with zero quasi-momentum and...
In this report the various approaches [1,2,3] to the state energy estimations for su-perheavy nuclei are discussed. In [1,2], for even-even nuclei, a correlation between the state energies and the deformation energies was found and parametrization of the correlation curve was obtained. For determination of extrapolation parameters the experimentally known energies of states were applied....
Application of zero-range two-body interactions in the three-body problem is not a trivial task, which manifests in appearance of Efimov or Thomas effects. One particular modification of zero-range interactions was suggested in the influential paper by Minlos and Faddeev [1] and was further analyzed in [2]. A main idea is to regularize the three-body problem by adding the effective three-body...
An approach based on the idea that the spinning nucleus being stretched out along the symmetry axis under the influence of some sort of centrifugal force has been proposed. Our approach led to the modified formula to describe the dependence of the moment of inertia on the angular momentum.
It is of interest to determine the mass-ratio, below which there are no bound states, for two-component system of two identical particles interacting with a distinct particle via contact interaction. Using the hyperradial expansion and taking into account that interaction is of zero range, the two-variable inequality was derived, which provides absence of bound states. The variable are mass...
We analyse superdeformed (SD) bands in 192Hg with the help of modified variable moment of inertia (VMI) model. In this, we obtain the values of unknown band-head spin (I0) along with the level spin. The band-head spin so estimated is not known experimentally in band-3. A total of 3 experimentally known SD bands of 192Hg have been analyzed. Quantitatively good results of the γ energies and the...
Potential splitting approach for scattering problem for few-body quantum systems
E.A. Yarevsky${}^1$, S.L. Yakovlev${}^1$
${}^1$St Petersburg State University, St Petersburg, Russia;
E-mail: e.yarevsky@spbu.ru
Scattering problem for few-body quantum systems is of great importance for various fields of modern quantum physics. The complicated boundary conditions at large distances,...
The Fayans energy-density functional.
New constraints from the equations of state.
I.N. Borzov 1,2, S.V. Tolokonnikov1,3
1 National Research Centre “Kurchatov Institute”, Moscow, Russia
2Bogolubov Laboratory of Theoretical Physics, Joint Institute of Nuclear Research, Dubna, Russia
3 Moscow Institute of Physics and Technology (National Research...
The calculations of neutron multiplicity distributions were carried out with the improved scission point model (ISPM) [1] for 252Cf, 248Cm, and 246Fm nuclei. Within the ISPM the probabilities of formation of different scission configurations as well as the available excitation energy at scission were found based on the calculation of the potential energy as a function of mass and charge...
Faddeev equations play an important role as a backbone of computational and theoretical models of quantum few-body systems in nuclear, atomic and molecular physics. Traditionally, they are used in the context of bound state and scattering calculations in stationary approach. The Faddeev decomposition of the operator can also be efficiently used for theoretical and numerical modeling of...
The shape and the size of a nucleus are among its most fundamental properties. Usually, isotopic dependence of nuclear radii is smooth, however the neutron-deficient isotopes in the lead region (near Z = 82) exhibit the richest manifestation of shape evolution and shape coexistence phenomena which lead to marked irregularities in the radii isotopic trends. The behavior of the ground and...
We discuss the efficient quantum-quasiclassical method developed by V.S. Melezhik with co-authors [1-4], which has been successfully applied to calculate various few-body processes and has made it possible to resolve a number of topical problems in atomic [1,3-5], mesoatomic [2], and nuclear physics [6]. In this approach, a few-body quantum problem is reduced to the simultaneous integration of...
The properties of the collective low-lying states of Zr isotopes indicate that some of these states are mainly spherical and the other are mainly deformed ones.
In one of our previous works, it was shown that the structure of low-lying collective states of $^{96}$Zr can be satisfactorily described within the framework of a geometric collective model based on the Bohr Hamiltonian with a...
The nondirect product discrete variable representation (npDVR) is developed for the time-dependent Schrödinger equation with non-separable angular variables and is applied to a hydrogen atom in elliptically polarized strong laser fields. The 2D npDVR is constructed on spherical harmonics orthogonalized on the 2D angular grids of the Popov and Lebedev 2D cubatures for the unit sphere [1]. With...
Atomic nuclei, to be drops of a Fermi liquid, have a number of properties in common with liquid drops of 3He atoms, as well as with electrons in metal clusters. For example, their energy levels have a similar shell structure and are characterized by the same magic numbers: 2, 8, 20 etc. [1]. Besides, they all contain an admixture of the two-fermion short-range correlations (2F-SRC) which are...
The standard Born-Oppenheimer approach to theoretical treatments of inelastic collision processes is the most widely used approach, despite many other methods have been proposed as well. It solves the problems into two steps: (1) the electronic structure calculations for fixed nuclei, and (2) nonadiabatic nuclear dynamical studies based on the potentials and couplings computed at the first...
Earlier, three-quasiparticle correlations in the ground state ($GSC_3$) were studied in [1,2] for static characteristics in the calculations of quadrupole moments in first excited 2^+ and 3^- states of Sn isotopes. Here we discuss $GSC_3$ for transitions with the energy $ω ≠0$ between these excited states. Calculations were performed for a large number of Sn isotopes. It was shown that,...
The Borromean system have a wide spread near nuclear driplines. These systems are of strong interest for theoretical and experimental studies because of their exotic properties, such as strong nuclear matter asymmetry and anomalous nuclear density (halo effect).
The cluster three body models usually provide good description of the borromean nuclei structure. In particular, three-body model...
The aim of present work is to study peculiar properties of the 12C(0+) and 12C(2+) energy spectrum associated with removal of Pauli forbidden states from the 3α functional space. A deep αα-potential of BFW [1] will be employed which has two Pauli forbidden states in the S wave and a single forbidden state in the D wave. A variational method on symmetrized Gaussian basis is employed. For the...
We investigate the Coulomb breakup of 11Be halo nuclei on a heavy target
(208Pb) from intermediate (70 MeV/nucleon) to low energies (5 MeV/nucleon) within the non-perturbative semiclassical and quantum-quasiclassical time-dependent approaches.
To quantify how good the semiclassical approach with decreasing the projectile energy is, we also performed calculations with quantum-quasiclassical...
We suggest the self-consistent description of the ground-state moment of inertia (MI) in highly prolate light nuclei 24Mg and 20Ne (with experimental equilibrium axial quadrupole deformations b2=0.605 and 0.72, respectively [1]). These nuclei provide an interesting opportunity to explore dependence of MI on the pairing, ground-state correlations and nuclear shape at extreme deformations. The...
We demonstrate the universality of the Random Matrix approach as a tool to detect the chaos-order transition in atomic nuclei. In particular, shell structure phenomenon in octupole deformed nuclei is discussed as the example of the interplay of regular and chaotic dynamics within the harmonic oscillator model with octupole deformations as the effective nuclear structure shell model [1]. It is...
The proton-nucleus elastic scattering at intermediate energies is a well-established method of investigating the nuclear matter distribution in stable nuclei. When performed in inverse kinematics with radioactive beams, it can be applied to the investigation of unstable nuclei as well.
Recently, differential cross sections for small-angle proton elastic scattering on the 12,14Be...
We consider fundamental aspects of nuclear physics and particle mass spectrum. The Standard Model with representation: SU(3)col × SU(2)L × U(1)Y [1] is the basic theory of all interactions. The Nonrelativistic Constituent Quark Model is a part of hadronic physics - an important component of the Standard model. The main NRCQM parameters are the pion mass mπ = 140 MeV, the initial constituent...
In our 4G model of final unification, along with three large atomic gravitational constants pertaining to electromagnetic, strong and weak interactions, we have proposed the existence of a strong nuclear charge of magnitude $e_s \cong 2.9463591e$ and existence of electroweak fermion of rest energy $M_wc^2\cong 584.725$ GeV. With reference to protons, pions and weak bosons, we noticed that,...
The probability of realization of xn channel is calculated for superheavy nuclei with Z > 114 using Monte Carlo method. The result is compared with the analytical expression based on assumption of Maxwellian distribution for neutron energy. The kinetic energy distribution of neutrons in multi-step decay process is analyzed and applied for the estimation of survival probabilities under xn, pxn,...
The project is motivated by the discrepancy (4%) between precise measurements of the proton charge rms-radius Rp = <RpE2>1/2 in the muonic hydrogen (μH atoms) Lamb shift experiments performed at Paul Scherrer Institute by the CREMA Collaboration (Rp = 0.84184(87) fm [1], Rp = 0.84087(39) fm [2]) and the radius determined in the electron–proton (ep) elastic scattering experiments: Rp =...
