Search

We consider the processes and reactions in the crusts of neutron star envelopes and analyze the density oscillations in the layers of this volume-centered crystalline structure, and the dynamics of stimulated reactions, including the transformations of nuclei. The action of acoustic waves that spread in the crystalline structure and can start up the different threshold reactions are considered. It is stated that the threshold reactions with capture of Fermi electrons in own cells by even-even nuclei stop after emission of two neutrinos. Other types of nuclei have also the own threshold cells, where the direct and inverse reactions can generate neutrino and anti-neutrino for a very long time. We believe this effect intensively contributes to the process of the neutron star rapid cooling.

In order to solve many-body states in a wide energy region including continuum states, it is strongly desiredto develop a useful method. In nuclear cluster systems [1, 2,], we must treat both bound and unbound statessimultaneously. For such calculations, we propose to apply symplectic coherent-state bases (SCSB). In thisreport, the basic idea of the SCSB method will be explained. Especially the Pauli exclusion principle playsan important role in nuclear systems [3, 4], and the orthogonality condition model (OSM) [5] has beenstudied successfully for various kinds of nuclear cluster systems. We here discuss an application of theSCSB to the OCM. The SCSB method can be easily applied to two-cluster systems. However, for multiclustersystems, the applicability of the SCSB is not self-evident. The multi-cluster system is described bythe Pauli-allowed states (PAS) [6] under the Pauli exclusion principle. In this report, the multi-cluster SCSBwill be discussed on the basis of the PAS of the multi-cluster systems.

To consider the interactions between light nuclei, as well as the nature of the nuclear forces between them, and the test was made of the coupled and resonant positions of the nucleus (_3^6)Li using the technique of the "Algebraic version of the resonant group method (AV RGM)", which takes into account the Pauli principle, and the cluster approximation. As a result, the nucleus (_3^6)Li was considered as a bound and resonant position formed by the interaction of two clusters. This approach can greatly facilitate the ongoing calculations, reducing the interaction between the set of nucleons, to the interaction of individual clusters. That’s way; the calculations carried out are an example of the applicability of this technique for studying interactions between light nuclei in the low-energy region up to 10 MeV. Also, special attention has the influence of nuclear forces, which are used for the description different nucleon-nucleon potentials. Consideration of the interaction between two clusters using alternately several different nucleon-nucleon potentials will allow us to better understand and determine the nature of nuclear force, which will be manifested through the obtained parameters of the bound and resonance positions, as well as the type of the built-up phase shifts. All calculations were performed using different values of nuclear parameters and quantum numbers. Calculations were carried out on the computer program "2cl_SpectrPhases.exe".

We investigate how the Coulomb interaction affects the energy $E$ and width $\Gamma$ of resonance states in mirror nuclei. We employ a three-cluster microscopic model to determine position of resonance states in two- and three-body continua. Two parameters are introduced to quantify effects of the Coulomb interactions. As the energy and width of the corresponding resonance states of mirror nuclei are displayed on an $E$-$\Gamma$ plane, these parameters determine a rotation and a dilatation. With the help of these parameters we found resonance states with strong, small and medium effects of the Coulomb interaction. We also found two different scenarios of the motion of resonance states due to the Coulomb interaction. The first standard (major) scenario represent resonance states with the larger energy and larger width than their counterparts have. The second rear scenario includes resonance states with the larger energy but smaller width., Comment: 55 pages, 22 figures, two new paragraphs are added and typos are corrected, submitted to Nucl. Phys . A

Human health is largely determined by the level of physical development and functionality of the body, the foundations of which are laid in childhood. Currently, social and environmental conditions, difficulties in organizing health care have led to an increase in all types of morbidity. Indicators of physical development decrease, the number of children with manifestations of acceleration of development decreases, at each fourth child the posture disturbance is noted. The disability of children is growing. Individuality of physical development and functional state of the body of children (boys and girls) certainly exists, it is the basis of well-known clinicians situations such as “paradoxical” reactions of the body, differences in the clinical picture of the disease at the same dose of infectious agent, abnormal effects in individuals and are referred to by clinicians as “individual features of the reactivity of the organism.” Based on this, in our work we use and present individual indicators of physical development (indicators of anthropometric status, external respiration, physical development and functional status) of the body of children with visual pathology, boys and girls of different ages. The physical condition of a person determines the degree of endo- and exointoxication and immunological reactivity. Therefore, the study of the impact of a new set of rehabilitation measures on immuno-hematological parameters that characterize the overall immunological reactivity of children aged 7-10 years with visual pathology is necessary to address its possible use. The aim of the study was to study the effect of the developed method of physical rehabilitation on the immunological reactivity of the body of children aged 7-10 years with visual pathology. Object and methods of research. Approbation of the complex method of physical rehabilitation carried out at children (31 children) aged 7-10 years of comprehensive special boarding school of I-III degrees № 23 (director Kotlyarov MV) Slavyansk under the control of medical workers of institution who carried out peripheral blood collection for laboratory examination of children on a hematology analyzer of the HB series, which was discussed in the previous section. Carrying out of rehabilitation measures of the method developed by us which is directed on improvement of physical development of these children and improvement of immunological reactivity of an organism of children, aged 7-10 years, with pathology of sight. For the rehabilitation of children with visual pathology of 7-10 years, we used the method of exercise for these children, developed plans based on the sex of deep disorders, and so on. The stage of the study of the use of this method in children with visual pathology 7-10 was found to influence the effects of rehabilitation measures on the immunological reactivity of the organism. First, the definitions summarize the impact on all adolescents with visual pathology, and then separately on boys and girls depending on age. Research results and their discussion. In children aged 7-10 years with visual pathology, who underwent a set of rehabilitation measures, the value of the index of the ratio of agranulocytes and ESR increases by 39.16%, which is evidence of stimulation of adaptive immune activity. This reduces the value of lymphocyte-granulocyte index by 12.20%, which confirms the activation of granulocyte leukocytes – neutrophilic polymorphonuclear leukocytes and eosinophils. Along with this, there is a tendency to decrease (P> 0.05) the index of immunological reactivity – by 10.71%, nonspecific resistance – by 12.20%, lymphocyte-granulocyte index – by 10.21%, the index of the ratio of lymphocytes and monocytes – at 11.49%. These changes in immuno-hematological parameters indicate that the rehabilitation measures in children aged 7-10 years with visual pathology, positively and slowly affect the overall immunological reactivity of the body of children with visual pathology. There is no immuno-hematological indicator that would indicate a negative impact on the physical development of the body and a significant decrease in immunohematological parameters that characterize the functional and immune status of children with visual pathology. Conclusions. Thus, the development of a set of rehabilitation measures for both boys and girls aged 7-10 years with visual pathology, improves immune and hematological parameters that characterize the state of nonspecific anti-infective and specific immune protection (immunological reactivity) of children aged 7-10 years with visual pathology. No changes in immuno-hematological parameters in these children, which could be a contraindication to the use of new sets of rehabilitation measures. Prospects for further research. The main scientific provisions obtained and presented in the article are the basis for studying the impact of measures and tools aimed at improving the state of non-specific anti-infective and specific immune protection (immunological reactivity) of children with visual pathology aged 10-14 years.

The theoretical analysis of structures of the bound and resonance states in 8Li and 8B nuclei is performed within a three-cluster microscopic model. In the framework of this model, 8Li and 8B nuclei are considered as three-cluster configurations 4He +3 H + n and 4He +3 He + p, respectively. A distinguished peculiarity of the model is that it allows us to consider the polarizability of weakly bound nuclei such as 7Li composed of an alpha particle and a triton or 7Be composed of an alpha particle and 3He. Gaussian and oscillator bases are used to expand the three-cluster wave function and to represent the many-channel Schr¨odinger equation in a matrix form. The main attention of the present study is paid to the effects of cluster polarization on the spectrum of bound and resonance states of 8Li and 8B and on the elastic and inelastic n +7Li and p +7Be scattering. It is shown that the cluster polarization has a great impact on parameters of the bound and resonance states in 8Li and 8B. For instance, it decreases the energy of resonance states by 0.7–2.0 MeV and increases their lifetime by more than three times. The roles of spin-orbital and Coulomb interactions in the formation of the spectrum of excited states in nuclei 8Li and 8B are studied in detail. In particular, it is found out that the Coulomb forces shift up the energy of resonance states in 8B with respect to the position of corresponding resonance states in 8Li and increases their widths., У рамках трикластерної моделi виконано теоретичний аналiз структури зв’язаних та резонансних станiв ядер 8Li i 8B. В цiй моделi ядро 8Li розглядається як трикластерна конфiгурацiя 4He+3H+n, а ядро 8B – як конфiгурацiя 4He+3He+p. Особливiсть даної моделi полягає у тому, що вона дає можливiсть враховувати поляризовнiсть слабкозв’язаних ядер, таких як ядро 7Li, яке складається iз альфа-частинки i тритона, або ядро 7Be, яке складається iз альфа-частинки i 3He. Гаусiвський та осциляторний базиси використовуються для розкладу трикластерної хвильової функцiї та для представлення у матричнiй формi рiвняння Шредiнгера для багатоканальної системи. Головна увага даних дослiджень придiляється впливу кластерної поляризацiї на спектр зв’язаних та резонансних станiв ядер 8Li i 8B та на пружне i непружне розсiяння n+7Li i p+7Be. Показано, що кластерна поляризацiя має великий вплив на параметри зв’язаних та резонансних станiв ядер 8Li i 8B. Наприклад, вона зменшує енергiю резонансних станiв на 0,7–2,0 МеВ та збiльшує їх час життя бiльш нiж у три рази. Детально дослiджена роль спiн-орбiтальної та кулонiвської взаємодiй у формуваннi спектра збуджених станiв ядер 8Li i 8B. Зокрема, виявлено, що кулонiвськi сили зсувають вгору енергiю резонансних станiв в ядрi 8B по вiдношенню до положень вiдповiдних резонансних станiв в 8Li, а також збiльшують їх ширину.

We investigate resonance states in three-cluster continuum of some light nuclei $^{9}$Be, $^{9}$B, $^{10}$B, $^{11}$B and $^{11}$C. These nuclei are considered to have a three-cluster configuration consisting of two alpha-particles and neutron, proton, deuteron, triton and nucleus $^{3}$He. In this study, we make use two different microscopic three-cluster models. The first model employs the Hyperspherical Harmonics basis to numerate channels and describe three-cluster continuum. The second model is the well-known complex scaling method. The nucleon-nucleon interaction is modeled by the semi-realistic Minnesota and Hasegawa-Nagata potentials. Our main aim is to find the Hoyle-analog states in these nuclei or, in other words, whether it is possible to synthesize these nuclei in a triple collision of clusters. We formulate the criteria for selecting such states and apply them to resonance states, emerged from our calculations. We found that there are resonance states obeying the formulated criteria which make possible syntheses of these nuclei in a stellar environment., 15 pages, 15 figures, submitted to Phys. Rev. C

We study the nature of the low-lying resonance states in mirror nuclei $^{9}\mathrm{Be}$ and $^{9}\mathrm{B}$. Investigations are performed within a three-cluster model. The model makes use of the hyperspherical harmonics, which provides a convenient description of the three-cluster continuum. The dominant three-cluster configurations $\ensuremath{\alpha}+\ensuremath{\alpha}+n$ and $\ensuremath{\alpha}+\ensuremath{\alpha}+p$ in $^{9}\mathrm{Be}$ and $^{9}\mathrm{B}$, respectively, are taken into account. Dominant decay channels for all resonance states in $^{9}\mathrm{Be}$ and $^{9}\mathrm{B}$ are explored. Much attention is paid to the controversial $1/{2}^{+}$ resonance states in both nuclei. We study effects of the Coulomb interaction on the energy and width of three-cluster resonances in the mirror nuclei $^{9}\mathrm{Be}$ and $^{9}\mathrm{B}$. We also search for the Hoyle-analog state, which is a key step for alternative ways to synthesize $^{9}\mathrm{Be}$ and $^{9}\mathrm{B}$ in triple collisions of clusters in a stellar environment.

We study nature of the low-lying resonance states in mirror nuclei $^{9}$Be and $^{9}$B. Investigations are performed within a three-cluster model. The model makes use of the hyperspherical harmonics, which provides convenient description of three-cluster continuum. The dominant three-cluster configurations $\alpha+\alpha+n$ and $\alpha+\alpha+p$ in $^{9}$Be and $^{9}$B, respectively, are taken into account. Dominant decay channels for all resonance states in $^{9}$Be and $^{9}$B are explored. Much attention is paid to the controversial $1/2^{+}$ resonance states in both nuclei. We study effects of the Coulomb interaction on energy and width of three-cluster resonances in the mirror nuclei $^{9}$Be and $^{9}$B. We also search for the Hoyle-analogue state which is a key step for alternative way of $^{9}$Be and $^{9}$B syntheses in a triple collision of clusters in a stellar environment., Comment: 17 pages, 16 figures, submitted to Phys. Rev. C

The spectra of low-lying states of the 9Be and 9B mirror nuclei in the excitation-energy range between 0 and 5 MeV are considered within the microscopic α + α + n(p) three-cluster model, which is a three-cluster variant of the algebraic version of the resonating-group method. Attention is given primarily to studying the nature of resonance states in a three-cluster continuum. A detailed comparison of the results obtained in this way with experimental data and with results of other microscopic calculations is performed.

We apply the microscopic three-cluster model, developed by the authors recently, to study the effects of cluster polarization on the capture reactions 3He(α, γ)7Be, 3H(α, γ)7Li, 6Li(p, γ)7Be, and 6Li(n, γ)7Li. These reactions are of great importance for astrophysical applications. Thus, the main attention is paid to the cross sections (or the astrophysical S factor) of the reactions in the low-energy region. Correlations between the astrophysical S factor of the reactions at zero energy and different quantities associated with the ground state of a compound nucleus are studied in detail.

PROCEEDINGS OF THE 4TH INTERNATIONAL WORKSHOP ON “STATE OF THE ART IN NUCLEAR CLUSTER PHYSICS” (SOTANCP4) 13–18 May 2018 Texas, USA, We investigate resonance states in three-cluster continuum of some light nuclei 9Be, 9B, 10B, 11B and 11C. These nuclei are considered to have a three-cluster configuration consisting of two alpha-particles and neutron, proton, deuteron, triton and nucleus 3He. In this study, we make use two different microscopic three-cluster models. The first model employs the Hyperspherical Harmonics basis to numerate channels and describe three-cluster continuum. The second model is the well-known complex scaling method. Our main aim is to find the Hoyle-analog states in these nuclei or, in other words, whether it is possible to synthesize these nuclei in a triple collision of clusters. We formulate the criteria for selecting such states and apply them to resonance states, emerged from our calculations. We found that there are resonance states obeying the formulated criteria which make possible syntheses of these nuclei in a stellar environment.

We investigate T-matrix for bound and continuous-spectrum states in the discrete oscillator representation. The investigation is carried out for a model problem – the particle in the field of a central potential. A system of linear equations is derived to determine the coefficients of the T-matrix expansion in the oscillator functions. We selected four potentials (Gaussian, exponential, Yukawa, and square-well ones) to demonstrate peculiarities of the T-matrix and its dependence on the potential shape. We also study how the T-matrix expansion coefficients depend on the parameters of the oscillator basis such as the oscillator length and the number of basis functions involved in calculations., Дослiджено властивостi Т-матрицi для зв’язаних станiв та станiв неперервного спектра у дискретному, осциляторному представленнi. Дослiдження проводяться для модельної проблеми – частинка в полi центрального потенцiалу. Виведено систему лiнiйних рiвнянь, розв’язок яких визначає коефiцiєнти розкладу Т-матрицi по осциляторних функцiях. Ми вибрали чотири потенцiали (гаусiвський, юкавiвський, експоненцiальний та потенцiал прямокутної ями) для демонстрацiї особливостей Т-матрицi та ї ї залежностi вiд форми потенцiалу. Ми також вивчаємо як коефiцiєнти розкладу Т-матрицi залежать вiд параметрiв осциляторного базису – осциляторної довжини та числа базисних функцiй, залучених у розрахунках.

The structure of $^8$He is investigated within a three-cluster microscopic model. The three-cluster configuration $\alpha+^2n+^2n$ was used to describe the properties of the ground state of the nucleus. The obtained results evidently indicate the existence of a neutron halo in $^8$He.