arXiv subjects

A. V. Dzhazairov-Kakhramanov

Publications and source records attributed to A. V. Dzhazairov-Kakhramanov.

At least 19 recordsLinked to original sources

arXiv2022

The $^6$Li$(p, γ)^7$Be reaction rate in the light of the new LUNA data

We present new calculations of the astrophysical $S-$factor and reaction rate for the $^{6}$Li$(p,γ)^{7}$Be reaction at energies of 10 keV to 5 MeV in the framework of a modified potential cluster model with forbidden states, including low lying resonances. The astrophysical $S(E)-$factor is compared with the available experimental data and calculations done within different models. The results for the $S-$factor are in good agreement with the data set (for $E<0.3$ MeV) and calculations (for $E<0.6$ MeV) of LUNA collaboration (Phys. Rev. C 102$,$ 052802, 2020). The recommended extrapolated zero value $S(0)$ turned out to be 101 eV $\cdot $ b. Using the theoretical total cross-sections$,$ the $^{6}$Li$(p,γ)^{7} $Be capture reaction rate is calculated at temperatures ranging from 0.01 to 10 $T_{9}$ and compared with NACRE and NACRE II. Analytical expressions for the $S-$factor and reaction rate are given, and the effect of low-lying resonances on the reaction rate is estimated. We suggest to update the NACRE and NACRE II databases in light of the new LUNA data and present calculations.

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arXiv2020

Reanalysis of $^{13}$N($p,γ$)$^{14}$O reaction and its role in stellar CNO cycle

Within the framework of the modified potential cluster model with forbidden states, the $^{13}$N($p,γ$)$^{14}$O reaction rate and the astrophysical $S$-factor are considered. It is shown that the first $p^{13}$% N resonance determines the $S$-factor and contributions of the $M1$ and $E2$ transitions are negligible at energies $E<1$ MeV, but are significant at high energies. The $S$-factor strongly depends on the $^{3}S_{1}$ resonance parameters. The influence of the width of \ the $^{3}S_{1}$ resonance on $S$% -factor is demonstrated. The reaction rate is calculated and an analytical approximation for the reaction rate is proposed. A comparison of our calculation with existing data is addressed. Results of our calculations for the $^{13}$N($p,γ)^{14}$O reaction rate provide the contribution to the steadily improving reaction rate database libraries. Our calculations of the $% ^{13}$N($p,γ)^{14}$O reaction rate along with results for the rates of $^{14}$N($% p,γ)^{15}$O and $^{12}$C$(p,γ)^{13}$N processes provide the temperature range $0.13<T_{9}<0.97$ for the conversion of CNO cycle to the HCNO cycle. Our results demonstrate that at early stages of a nova explosion at temperatures about $0.1$ $T_{9}$ and at late stages of evolution of supermassive stars at temperatures about $1.0$ $T_{9}$ the ignition of the HCNO cycle could occur at much lower densities of a stellar medium.

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arXiv2020

The comparative role of 7Li(n,γ) reaction in primordial nucleosynthesis

Within the framework of the modified potential cluster model with forbidden states and their classification according to Young diagrams, the possibility of describing experimental data on the total cross sections of the neutron radiative capture on 7Li is considered. It is shown that the model used and the methods for constructing potentials make it possible to correctly describe the behavior of experimental cross sections at energies of 5 meV (5 10-3 eV) to 1 MeV(1 10+6 eV), where experimental data are available. Based on the obtained total cross sections up to 5 MeV, the reaction rate was calculated and its analytical approximation was carried out. It was shown that the 7Li(n,g)8Li reaction dominates at T9 < 0.1-0.2 as against with the burning of 7Li in reactions 7Li(3H,n)9Be and 7Li(4He,g)11B.

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arXiv2020

12B(n,gamma)13B reaction as alternative path to astrophysical synthesis of 13C isotope

The total cross sections of the neutron radiative capture on 12B at astrophysical energies to the ground state of 13B have been calculated in the energy range of 10E-8 to 10 MeV within the framework of a modified potential cluster model with the classification of orbital states according to Young diagrams. Reaction rates in the temperature range of 0.01 to 10 T9 and their analytical parameterization were obtained. The calculated rates of 12B(n,gamma)13B excess the previous results by approximately to one order. Cross sections and reaction rates of 12C(n,gamma)13C are calculated and compared to the n10B, n11B, n12B, and p12C reaction rates. It is proposed that obtained rates of the 12B(n,gamma)13B reaction should be taken into account in novel scenarios of stable isotope 13C synthesis without of 12C hydrogen burning.

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arXiv2020

Influence of resonances on the 11B(n,gamma)12B capture reaction rate. Capture to the ground state of 12B

Within the framework of the modified potential cluster model with a classification of orbital states according to Young diagrams, the possibility of describing experimental data for total cross sections of the neutron radiative capture on 11B to the ground state of 12B at energies of 10 meV (1 meV = 10-3 eV) to 7 MeV was considered. It was shown that, taking into account only the E1 transition from the S state of the n11B scattering to the ground state of 12B, it is quite possible to explain the magnitude of the known experimental cross sections at energies of 25.3 meV to 70 keV. Furthermore, on the basis of the total cross sections of 10 meV to 7 MeV, but excluding resonances above 5 MeV, the reaction rate is calculated in the temperature range of 0.01 to 10.0 T9. It is shown that the inclusion of low-lying resonance states makes a significant contribution to the reaction rate, starting already with temperatures of 0.2-0.3 T9.

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arXiv2020

Role of resonances in the 8li(p,g)9be capture on reaction rate of the relevant astrophysical synthesis of 9be

The total cross sections of the radiative proton capture on 8Li at astrophysical energies were considered in the framework of the modified potential cluster model with forbidden states, with the classification of the orbital cluster states according to Young diagrams. The recalculation of total cross sections for the 9Be(γ,p0)8Li photodisintegration was used as experimental data. In whole, it is possible to obtain the available data on cross sections at energies to 7.0 MeV. Astrophysical S-factors and reaction rates at the temperature range of 0.01 to 10 T9 were calculated. It was shown that the resonances in the p8Li scattering channel considerably influence to the reaction rate and, in the first place, the first - at 87 keV. The analytical parametrization was obtained for calculated reaction rate.

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arXiv2019

Influence of resonances on the $^{11}$B(n,gamma)$^{12}$B capture reaction rate. III. Capture to the 2nd, 3rd and 4th excited state of $^{12}$B

Within the framework of the modified potential cluster model with a classification of orbital states according to Young diagrams, the possibility of data description of the radiative neutron capture on 11B to the second excited state of 12B at 1.67365 MeV (2-) and prediction absentee of experimental data for the total cross sections to the third and fourth excited state of 12B at 2.6208 MeV (1-) and 2.723 MeV (0+) for reaction energy of 10 meV (1 meV = 10-3 eV) to 7 MeV was considered. The reaction rate in the temperature range of 0.01 to 10.0 T9 is calculated on the basis of obtained cross sections, which take into account resonances up to 5 MeV. It is shown, that low-lying resonances exercise a significant influence to the capture reaction rate. The approximation of the calculation reaction rate is carried out by the simple analytic formula.

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arXiv2019

Influence of resonances on the 11B(n,g)12B capture reaction rate. II. Capture to the first excited state of 12B

Within the framework of the modified potential cluster model with a classification of orbital states according to Young diagrams, the possibility of prediction absentee experimental data for the total cross sections of the radiative neutron capture on 11B to the first excited state 12B at 0.95 MeV (2+) for reaction energy of 10 meV (1 meV = 10-3 eV) to 7 MeV. The reaction rate in the temperature range of 0.01 to 10.0 T9 is calculated on the basis of obtained cross sections, which take into account resonances up to 5 MeV. It is shown that low-lying resonances exercise a significant influence to the capture reaction rate. The approximation of the calculation reaction rate is carried out by the simple analytic formula.

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arXiv2018

New results for radiative 3He(2H,gamma)5Li capture at astrophysical energy and its possible role in accumulation of 6Li at the BBN

Big Bang Nucleosynthesis (BBN) relevance reactions 3He(2H,γ)5Li, 3H(3He,γ)6Li, 5Li(n,γ)6Li as a key to approach for scenario of 6Li formation are treated. The rates of reaction for these processes are analyzed. Comparison of the reactions rates and the prevalence of light elements leads to the assumption that the two-step process 2H + 3He --> 5Li + γ and n + 5Li --> 6Li + γ can make a significant contribution to the formation of 6Li at the BBN at least at temperatures T9 of the order of unity. Calculations of the total cross sections, astrophysical S-factor, and reaction rates have been performed for 3He(2H,γ)5Li radiative capture within the modified potential cluster model with forbidden states, which follow from the classification of the orbital cluster states according to Young diagrams. Numerical data and corresponding parametrizations cover the energy range up to 5 MeV and temperature range T9<10. An updated compilation of detailed data for the reaction 3He(2H,γ)5Li are presented.

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arXiv2018

Whether the excited cluster 14N* exists in 15O nucleus?

Within the modified potential cluster model with forbidden states effectively taking into account the Pauli Exclusion Principle the astrophysical S-factor of radiative p14N capture to 15O ground state has been calculated. The calculation was performed at the proton energy up to 5 MeV in the center of mass system (c.m.) with taking into account broad resonances up to 3.4 MeV in c.m. To explain reasonably the available experimental data it is required to admit the existence of 14N cluster in excited state 14N* with the excitation energy equal to 5.69 MeV and momentum JP = 1-. It is assumed that in this case the 4D1/2 state wave function of the p14N* clusters relative motion may be used. There was shown that it is succeeded to describe the S-factor of p14N capture in the resonance region only under the assumption that all low-lying resonances at 260(1/2+), 987(3/2+), 1447(1/2+), 2187(3/2+), and 3211(3/2+) keV in c.m. are the 4D1/2 and 4D3/2 scattering waves.

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arXiv2018

New results for the astrophysical S-factor and reaction rate of radiative 3He4He capture

In the frame of modified potential cluster model based on the classification of orbital states by Young diagrams and revised interaction potential parameters for the bound states of 7Be in 3He4He cluster model with forbidden states the astrophysical S-factor for the radiative capture reaction has been calculated from the 10 keV. Obtained results S(23 keV) = 0.561 keV b reproduce the latest experimental data at 23 keV. Calculated and parametrized reaction rate is compared to some results known in the range of temperatures from 0.05 to 5 T9.

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arXiv2018

New Results for Neutron Radiative Capture on 10be at Energies from 25.3 meV to 10.0 meV

It is shown that in the framework of the modified potential cluster model we succeeded in correct describing the available experimental data for neutron radiative capture on 10Be total cross-sections at low, astrophysical and thermal energies. All interaction potentials for different partial waves are constructed by describing the basic characteristics of the bound states and spectra of final nucleus. Experimental data for the total cross-sections of the neutron radiative capture on 10Be were obtained by using known data for reduced probabilities of 11Be Coulomb dissociation.

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arXiv2016

New results for reaction rate of the proton radiative capture on 3H

Calculations of the reaction rate of the proton radiative capture on 3H at temperatures from 0.01 T9 up to 5 T9, which are based on the theoretical results for the astrophysical S-factor and take into account the latest experimental data, were carried out. Theoretical results for the S-factor at energies from 1 keV up to 5 MeV were obtained in the framework of the modified potential cluster model with the classification of orbital states according to Young tableaux. On the basis of used nuclear model of the interaction of p and 3H particles there was shown possibility of description the latest experimental data for the S-factor at the energy range from 50 keV up to 5 MeV.

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arXiv2015

The radiative 10Be(n,g)11be capture at thermal and astrophysical energies

Within the framework of the modified potential cluster model with the forbidden states and the classification of states according to Young tableaux the possibility of describing the available experimental data for the total reaction cross sections of the neutron radiative capture on 10Be at thermal and astrophysical energies was shown.

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arXiv2015

8li(n,g)9li reaction at superlow energies

Within the framework of the modified potential cluster model with the state classification of nuclear particles according to Young tableaux the possibility of describing the available experimental data for the total cross sections of the neutron radiative capture on 8Li at thermal and astrophysical energies was considered.

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arXiv2015

Thermonuclear Processes for Three Body System in the Potential Cluster Model

The manuscript is devoted to the description of the results obtained in the frame of the modified potential cluster model with the classification of states according to Young tableaux for neutron and proton radiative capture processes on 2H at thermal and astrophysical energies. It demonstrates methods of application that were obtained on the basis of phase shift analysis and characteristics of the bound states of 2H potentials for consideration of the radiative capture processes. First reaction of the proton capture directly takes part in the pp solar cycle, where it is the second reaction. The neutron capture is not a part of usual thermonuclear cycles in the Sun and stars, but can take part in the processes of primordial nucleosynthesis, following at formation and evolution of our entire Universe.

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arXiv2014

Phase Shift Analysis of the p14C Scattering at the Energy of the 2S1/2 Resonance

The phase shift analysis for determination of the 2S1/2 resonance at 1.5 MeV was carried out on the basis of the known experimental measurements of the excitation functions of the p14C elastic scattering at four angles from 90 to 165 grad. and more than 100 energy values in the range from 600-800 to 2200-2400 keV. The obtained shape of the resonance 2S1/2 phase shift coincides with the characteristics of the corresponding level of 15N in whole, and the suggested potential acceptably describe this scattering phase shift.

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arXiv2014

Photoprocesses on the 6Li nucleus in the potential cluster model

The photodisintegration of the 6Li nucleus through the channels 3He3H, 4He2H and the corresponding radiative capture are considered in simple two-cluster models. Potentials with forbidden states which reproduce the phase shifts of elastic scattering up to energies of 20 MeV are was used to describe cluster interactions. It is shown that such the potential cluster model provides an accurate description of total cross sections for photonuclear processes over the entire energy region under consideration.

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