2020 год
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№ |
Название статьи |
Авторы |
Год |
Название журнала |
Краткая аннотация |
| 1 |
Determination of the primary energy using an ultrathin calorimeter |
Elena Dmitrieva, Anastasiya Fedosimova, Igor Lebedev, Abzal Temiraliev, Medeu Abishev, Tolegen Kozhamkulov, Andrey Mayorov and Claudio Spitaleri |
2020 |
J. Phys. G: Nucl. Part. Phys. 47 035202, Q2 |
An approach for measuring energy of cosmic-ray particles with energies E > 1012 eV using an ultrathin calorimeter is presented. The method is based on the analysis of the correlation dependence of the cascade size on the rate of development of the cascade process. In order to determine the primary energy, measurements are made based on the number of secondary particles in the cascade, N e, at two observation levels Z 1 and Z 2, separated by an absorber layer. Based on the obtained measurements, a correlation analysis of the dependence of logN e(Z 1) on the difference d N = logN e(Z 1) - logN e(Z 2) is carried out. The correlation curves (logN e from d N) in the negative part of the dN axis are almost parallel to each other and practically do not depend on the depth of the cascade development. It makes it possible to determine the primary energy using an ultrathin calorimeter. The best option for applying the method is a calorimeter, which has a unit with a heavy target, leading to the rapid development of the cascade, and a homogeneous measuring and absorption block. |
| 2 |
Volkov–Akulov–Starobinsky supergravity revisited |
Aldabergenov, Y. |
2020 |
European Physical Journal C |
We find new realizations of Volkov–Akulov–Starobinsky supergravity, i.e. Starobinsky inflationary models in supergravity coupled to a nilpotent superfield describing Volkov–Akulov goldstino. Our constructions are based on the no-scale Kähler potential K= - 3 log (T+ T¯) for the inflaton field, and can describe de Sitter vacuum after inflation where supersymmetry is broken by the goldstino auxiliary component. In fact, we show that a more general class of models with K= - αlog (T+ T¯) for 3 ≤ α≲ 6.37 can accomodate Starobinsky-like inflation with the universal prediction ns≃1-2Ne and r≃4α(α-2)2Ne2, while for 6.37 ≲ α≲ 7.23 viable hilltop inflation is possible (with ns and r close to the above expressions). We derive the full component action and the masses of sinflaton, gravitino, and inflatino that are generally around the inflationary Hubble scale. Finally, we show that one of our models can be dualized into higher-derivative supergravity with constrained chiral curvature superfield. |
| 3 |
Aspects of gauged R symmetry in SU (1,1) /U (1) supergravity |
Aldabergenov, Y. |
2020 |
Physical Review D https://doi.org/10.1103/PhysRevD.101.015016
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We propose a novel realization of spontaneous supersymmetry breaking in de Sitter vacuum by F- and D-terms in N=1 four-dimensional supergravity coupled to a chiral superfield with SU(1,1)/U(1) target space. Our construction features gauged U(1)R symmetry rotating the chiral scalar field by a phase. Both supersymmetry and R-symmetry can be spontaneously broken, and for two particular parameter choices we obtain no-scale supergravity with positive tunable cosmological constant. |
| 4 |
Minimal Starobinsky supergravity |
Yermek Aldabergenov, Shuntaro Aoki, |
2020 |
Physical Review D 101 |
The minimal Starobinsky supergravity with inflaton (scalaron) and goldstino in a massive vector supermultiplet is coupled to the dilaton-axion chiral superfield with the no-scale Kähler potential and a superpotential. The Kachru-Kallosh-Linde-Trivedi-type superpotential with a constant term is used to stabilize dilaton and axion during inflation, but it is shown to lead to an instability. The instability is cured by adding the alternative Fayet-Iliopoulos (FI) term that does not lead to the gauged R symmetry. Other stabilization mechanisms, based on the Wess-Zumino-type superpotential, are also studied in the presence of the FI term. A possible connection to the D3-brane models is briefly discussed too. |
| 5 |
Primordial black holes from |
Yermek Aldabergenov, |
2020 |
European Physical |
The modified supergravity approach is applied to describe a formation of Primordial Black Holes (PBHs) after Starobinsky inflation. Our approach naturally leads to the two-(scalar)-field attractor-type double inflation, whose first stage is driven by scalaron and whose second stage is driven by another scalar field which belongs to a supergravity multiplet. The scalar potential and the kinetic terms are derived, the vacua are studied, and the inflationary dynamics of those two scalars is investigated. We numerically compute the power spectra and we find the ultra-slow-roll regime leading to an enhancement (peak) in the scalar power spectrum. This leads to an efficient formation of PBHs. We estimate the masses of PBHs and we find their density fraction (as part of Dark Matter). We show that our modified supergravity models are in agreement with inflationary observables, while they predict the PBH masses in a range between 10 16 g and 10 20 g. In this sense, modified supergravity provides a natural top-down approach for explaining and unifying the origin of inflation and the PBHs Dark Matter. |
| 6 |
New measurements and reanalysis of 14N elastic scattering on 10B target |
Nassurlla M., Burtebayev N., |
2020 |
Chinese Physics C, V.44(10), P.104103, Q2 |
The angular distributions of elastic scattering of 14N ions on 10B targets have been measured at incident beam energies of 21.0 and 24.5 MeV. Angular distributions at higher energies 38-94.0 MeV (previously measured) were also included in the analysis. All data were analyzed within the framework of the optical model and the distorted waves Born approximation method. The observed rise in cross sections at large angles was interpreted as a possible contribution of the α-cluster exchange mechanism. Spectroscopic amplitudes SA2 and SA4 for the configuration 14N→ 10B +α were extracted. Their average values are 0.58±0.10 and 0.81±0.12 for SA2 and SA4, respectively, suggesting that the exchange mechanism is a major component of the elastic scattering for this system. The energy dependence of the depths for the real and imaginary potentials was found. |
| 7 |
Neutrino oscillation |
Boshkayev K., |
2020 |
European Physical Journal C, |
We investigate neutrino oscillation in the field of an axially symmetric space-time, employing the so-called q-metric, in the context of general relativity. Following the standard approach, we compute the phase shift invoking the weak and strong field limits and small deformation. To do so, we consider neutron stars, white dwarfs and supernovae as strong gravitational regimes whereas the solar system as weak field regime. We argue that the inclusion of the quadrupole parameter leads to the modification of the well-known results coming from the spherical solution due to the Schwarschild space-time. Hence, we show that in the solar system regime, considering the Earth and Sun, there is a weak probability to detect deviations from the flat case, differently from the case of neutron stars and white dwarfs in which this probability is larger. Thus, we heuristically discuss some implications on constraining the free parameters of the phase shift by means of astrophysical neutrinos. A few consequences in cosmology and possible applications for future space experiments are also discussed throughout the text. |
| 8 |
Accretion disc luminosity for black holes surrounded by dark matter |
Boshkayev K., Idrissov A., |
2020 |
Monthly Notices of the Royal Astronomical Society, |
We consider the observational properties of a static black hole space-time immersed in a dark matter envelope. We investigate how the modifications to geometry induced by the presence of dark matter affect the luminosity of the black hole's accretion disc. We show that the same disc luminosity as produced by a black hole in vacuum may be produced by a smaller black hole surrounded by dark matter under certain conditions. In particular, we demonstrate that the luminosity of the disc is markedly altered by the presence of dark matter, suggesting that the mass estimation of distant supermassive black holes may be changed if they are immersed in dark matter. We argue that a similar effect holds in more realistic scenarios, and we discuss the refractive index related to dark matter lensing. Finally, we show how the results presented here may help to explain the observed luminosity of supermassive black holes in the early Universe. |
| 9 |
Swelling of Doubly Magic Ca 48 Core in Ca Isotopes beyond N=28 |
Tanaka M., Burtebayev N., Nassurlla Maulen, Kenzhina I., T. K. Zholdybayev, et al. |
2020 |
Physical Review Letters Volume 124, Issue 10, 13 id 1950028, Q1 https://doi.org/10.1103/PhysRevLett.124.102501
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Interaction cross sections for Ca42-51 on a carbon target at 280 MeV/nucleon have been measured for the first time. The neutron number dependence of derived root-mean-square matter radii shows a significant increase beyond the neutron magic number N=28. Furthermore, this enhancement of matter radii is much larger than that of the previously measured charge radii, indicating a novel growth in neutron skin thickness. A simple examination based on the Fermi-type distribution, and mean field calculations point out that this anomalous enhancement of the nuclear size beyond N=28 results from an enlargement of the core by a sudden increase in the surface diffuseness of the neutron density distribution, which implies the swelling of the bare Ca48 core in Ca isotopes beyond N=28. |
| 10 |
Recent developments of TiO2-based photocatalysis in the hydrogen evolution and photodegradation: A review |
Bakbolat, B., Daulbayev, C., Sultanov, F., Bekbaev, A., Chuprakov, I, et al. |
2020 |
The growth of industrialization, which is forced to use non-renewable energy sources, leads to an increase in environmental pollution. Therefore, it is necessary not only to reduce the use of fossil fuels to meet energy needs but also to replace it with cleaner fuels. Production of hydrogen by splitting water is considered one of the most promising ways to use solar energy. TiO2 is an amphoteric oxide that occurs naturally in several modifications. This review summarizes recent advances of doped TiO2-based photocatalysts used in hydrogen production and the degradation of organic pollutants in water. An intense scientific and practical interest in these processes is aroused by the fact that they aim to solve global problems of energy conservation and ecology. |
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| 11 |
Determination of the enhancement factor and the electron screening potential in the D(3He,p)4He reaction using TiD targets. |
V. M. Bystritsky, D. K. Chumakov, G. N. Dudkin, M. Filipowicz, A. R. Krylov, B. A. Nechaev, A. Nurkin, V. N. Padalko, F. M. Pen’kov, A. V. Philippov, Yu. Zh. Tuleushev, V. A. Varlachev & E. A. Zhakanbaev |
2020 |
The European Physical Journal A, volume 56. Article number: 60 (2020), Q2 https://doi.org/10.1140/epja/s10050-020-00038-7
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The study of fusion reactions D(d,p)3HD(d,p)3H, D(d,n)3HeD(d,n)3He, T(d,n)3HeT(d,n)3He, 3He(d,p)4He3He(d,p)4He, and D(3He,p)4HeD(3He,p)4He at astrophysical energies is of interest for both basic and applied physics. These studied provide information on electron screening of nuclear reactions that provide important information on the role of electrons in reactions induced by deuterons, tritons, and nuclei of helium isotopes that proceed in reactors. The D(3He,p)4HeD(3He,p)4He reaction was investigated at the pulsed plasma Hall accelerator (Tomsk) in the 3He+3He+ ion energy range EHe=16÷34EHe=16÷34 keV (laboratory reference frame) with a step of 2 keV. The goal of this work was to determine experimentally the enhancement factor of the D(3He,p)4HeD(3He,p)4He reaction and the electron screening potential UeUe using a TiD targets with Miller indices [111] and [100]. A strong impact of the target crystal structure on reaction enhancement factor was discovered. We believe that solid-state effects make the largest contribution to the behavior of the enhancement factor D(3He, p)4HeD(3He, p)4He of the reaction as a function of energy. One of these effects is the particle channeling in crystal structures. An unexpected increase of the enhancement factors for the D(3He, p)4HeD(3He, p)4He reaction in the energy range 16÷2216÷22 keV probably indicates the emergence of some new mechanism that increases the yield of the reaction with lowering energy. |
| 12 |
Reanalysis of the N 13 (p,γ) O 14 reaction and its role in the stellar CNO cycle |
Dubovichenko, S.B., Kezerashvili, R.Y., Burkova, N.A., Dzhazairov-Kakhramanov, A.V., Beisenov, B. |
2020 |
Within the framework of the modified potential cluster model with forbidden states, the N13(p,γ)O14 reaction rate and the astrophysical S factor are considered. It is shown that the first p13 N resonance determines the S factor and contributions of the M1 and E2 transitions are negligible at energies E<1MeV, but are significant at high energies. The S factor strongly depends on the S13 resonance parameters. The influence of the width of the S13 resonance on the 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 N13(p,γ)O14 reaction rate provide the contribution to the steadily improving reaction-rate database libraries. Our calculations of the N13(p,γ)O14 reaction rate along with results for the rates of the N14(p,γ)O15 and C12(p,γ)N13 processes provide the temperature range 0.13 |
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| 13 |
Influence of resonances on |
Dubovichenko, S.B., Burkova, N.A., |
2020 |
Astroparticle Physics, https://doi.org/10.1016/j.astropartphys.2020.102481
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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. |
| 14 |
Reaction rate of p14N → 15Oγ capture to all bound states in potential cluster model |
Dubovichenko, S., Burkova, N., Dzhazairov-Kakhramanov, A., Beysenov, B. |
2020 |
International Journal of Modern Physics E, 2020, 29(1), 1930007, Q2 |
Review of calculation results for astrophysical S-factor of the 14N(p,γ)15O capture reaction in the p14N channel of 15O was presented. It was carried out in the frame of the modified potential cluster model (MPCM) taking into account resonances in the 15O spectrum up to 3.2MeV at energy of incident protons varying of 30keV to 5MeV. It is possible to describe experimental data for the astrophysical S-factors of the radiative proton capture on 14N to five excited states of 15O at excitation energies of 5.18MeV to 6.86MeV, only under assumption, that all five resonances are D scattering waves. Quality new physical interpretation of the capture mechanism is discussed in this channel to the ground state of 15O. We assumed that the ground state of 15O is determined by the p14N∗ channel with excited 14N∗ cluster, which immediately allowed us to correctly describe order of values of the experimental S-factor for capture to this state. Taking into account these results, the total S-factor of the proton capture on 14N and the reaction rates to the ground and five excited states of 15O were determined at temperatures of 0.01T9 to 10T9. The parametrization of the total reaction rate with a simple form is performed, which allows as to obtain χ2 equal to 0.06 with 5% errors of the calculated rate. |
| 15 |
Proca tubes with the flux of the longitudinal chromoelectric field and the energy flux/momentum density |
Vladimir Dzhunushaliev, Vladimir Folomeev |
2020 |
Eur. Phys. J. C, (2020) 80:1043, Q1 |
We consider non-Abelian SU(3) Proca theory with a Higgs scalar field included. Cylindrically symmetric solutions describing classical tubes either with the flux of a longitudinal electric field or with the energy flux (and hence with nonzero momentum density) are obtained. It is shown that, in quantum Proca theory, there can exist tubes both with the flux of the longitudinal electric field and with the energy flux/momentum density simultaneously. An imaginary particle – Proca proton – in which ‘quarks’ are connected by tubes with nonzero momentum density is considered. It is shown that this results in the appearance of the angular momentum related to the presence of the non-Abelian electric and magnetic fields in the tube, and this angular momentum is a part of the Proca proton spin. |
| 16 |
Spinor field solutions in F(B2) modified Weyl gravity |
Vladimir Dzhunushaliev, Vladimir Folomeev |
2020 |
International Journal of Modern Physics D Vol. 29, No. 13 (2020) 2050094 (17 pages), Q2 |
We consider modified Weyl gravity where a Dirac spinor field is nonminimally coupled to gravity. It is assumed that such modified gravity is some approximation for the description of quantum gravitational effects related to the gravitating spinor field. It is shown that such a theory contains solutions for a class of metrics which are conformally equivalent to the Hopf metric on the Hopf fibration. For this case, we obtain a full discrete spectrum of the solutions and show that they can be related to the Hopf invariant on the Hopf fibration. The expression for the spin operator in the Hopf coordinates is obtained. It is demonstrated that this class of conformally equivalent metrics contains the following: (a) a metric describing a toroidal wormhole without exotic matter; (b) a cosmological solution with a bounce and inflation and (c) a transition with a change in metric signature. A physical discussion of the results is given. |
| 17 |
Thermodynamics and statistical physics of quasiparticles within the quark gluon plasma model |
Vladimir Dzhunushaliev, Vladimir Folomeev, Tlekkabul Ramazanov and Tolegen Kozhamkulov |
2020 |
Modern Physics Letters A, Vol. 35, No. 23 (2020) 2050194 (19 pages), Q2 |
We consider thermodynamic properties of a quark-gluon plasma related to quasiparticles having the internal structure. For this purpose, we employ a possible analogy between quantum chromodynamics and non-Abelian Proca-Dirac-Higgs theory. The influence of characteristic sizes of the quasiparticles on such thermodynamic properties of the quark-gluon plasma like the internal energy and pressure is studied. Sizes of the quasiparticles are taken into account in the spirit of the van der Waals equation but we take into consideration that the quasiparticles have different sizes, and the average value of these sizes depends on temperature. It is shown that this results in a change in the internal energy and pressure of the quark-gluon plasma. Also, we show that, when the temperature increases, the average value of characteristic sizes of the quasiparticles increases as well. This leads to the occurrence of a phase transition at the temperature at which the volume occupied by the quasiparticles is compared with the volume occupied by the plasma. |
| 18 |
Non-Abelian Proca theories with extra fields: particlelike and flux tube solutions |
Vladimir Dzhunushaliev, Vladimir Folomeev, Tlekkabul Ramazanov, Arislan Makhmudov and Tolegen Kozhamkulov |
2020 |
Phys. Scr. 95 (2020) 074013 (7pp), Q2 |
We consider non-Abelian Proca theories with extra fundamental fields included. In the case of SU(2) Proca theory with nonlinear scalar and spinor fields, we obtain spherically symmetric regular solutions describing particlelike configurations with finite energy. For such systems, we find the energy spectrum and show the presence of a mass gap. In the case of SU(3) Proca theory with a nonlinear scalar field, we obtain cylindrically symmetric solutions describing tubes either with the flux of a longitudinal electric field or with the energy flux or with both of them. It is shown that the tubes with the energy flux may contribute considerably to the Proca proton spin. Consistent with all of this, we have argued that non-Abelian Proca theories containing extra fields may approximately describe some phenomena in QCD. |
| 19 |
Measurements of the low-energy neutron and gamma ray accompaniment of extensive air showers in the knee region of primary cosmic ray spectrum |
A. Shepetov, A. Chubenko, B. Iskhakov, O. Kryakunova, O. Kalikulov, S. Mamina, K. Mukashev, V. Piscal, V. Ryabov, N. Saduyev, T. Sadykov, N. Salikhov, E. Tautaev, L. Vil'danova, V. Zhukov |
2020 |
European Physical |
Purposeful investigation of radiation fluxes strongly delayed in relation to the main particle front of extensive air shower (EAS) was undertaken at the Tien Shan Mountain Cosmic Ray Station. It was found that the passage of the EAS can be accompanied by the delayed thermal neutrons and by the soft (30–50) keV gamma rays, mostly concentrated within a region of about (5–10) m around the shower axis, where the integral radiation fluence can vary in the limits of (10 - 4- 1) cm- 2 for neutrons, and of (0.1 - 1000) cm- 2 for gamma rays. The dependence of signal multiplicity on the shower size Ne has a power shape both for the neutron and gamma ray components, with a sharp increase of its power index around the value of Ne≈ 10 6, which corresponds to the position of the 3 × 10 15 eV knee in the primary cosmic ray spectrum. The total duration of detectable radiation signal after the EAS passage can be of some tens of milliseconds in the case of neutron component, and up to a few whole seconds for gamma rays. The delayed accompaniment of low-energy radiation particles can be an effective probe to study the interaction of the hadronic component of EAS. |
| 20 |
Dirac star with SU(2) Yang-Mills and Proca fields |
V. Dzhunushaliev, V. Folomeev |
2020 |
PHYSICAL REVIEW D 101, 024023 (2020), Q1 |
We study spherically symmetric strongly gravitating configurations supported by nonlinear spinor fields and non-Abelian SU(2) Yang-Mills/Proca magnetic fields. Regular asymptotically flat solutions describing objects with positive Arnowitt-Deser-Misner masses are obtained numerically. When the mass of the spinor fields is much smaller than the Planck mass, we find approximate solutions that can describe systems with total masses comparable to the Chandrasekhar mass and with effective radii of the order of kilometers. For the values of the system free parameters used here, we show that the SU(2) magnetic field always gives a small contribution to the total energy density and mass of the configurations under investigation. From the astrophysical point of view, one can regard such objects as magnetized Dirac stars. |
| 21 |
Thick branes in higher-dimensional f(R) gravity |
V. Dzhunushaliev, V. Folomeev, G. Nurtayeva and S. D. Odintsov |
2020 |
International Journal of Geometric Methods in Modern Physics, Vol. 17, No. 3 (2020) 2050036 (17 pages), Q2 |
We study the thick brane model within f(R) Rn the modified gravity in D-dimensional spacetimes with D ≥ 6. The system under consideration consists of two branes orthogonal to each other: the four-dimensional Lorentzian brane and (D - 5)-dimensional Euclidean one. It is numerically shown that, for a given D, regular vacuum asymptotically anti-de Sitter solutions exist only in the range 1 < n < D/2. Depending on the values of n and boundary conditions imposed on the Lorentzian brane, the solutions can pass or not pass through a fixed point located on the Lorentzian brane, and also be Z2-symmetric or nonsymmetric. In the large-D limit, we find the approximate analytic solutions. It is also shown that a test scalar field is trapped on the Lorentzian brane at any D. |
| 22 |
Evaluation of tritium release into primary coolant for research and testing reactors |
Kenzhina, I., Ishitsuka, E., Okumura, K., Takemoto, N., Chikhray, Y, et al. |
2020 |
Journal of Nuclear Science and Technology, 2020, стр. 1–12, Q2 |
The sources and mechanisms for the tritium release into the primary coolant in the JMTR and the JRR-3M containing beryllium reflectors are evaluated. It is found that the recoil release from chain reaction of 9Be is dominant and its calculation results agree well with trends derived from the measured variation of tritium concentration in the primary coolant. It also indicates that the simple calculation method used in this study for the tritium recoil release from the beryllium reflectors can be utilized for an estimation of the tritium release into the primary coolant for a water-cooled research and testing reactors containing beryllium reflectors. © 2020, © 2020 Atomic Energy Society of Japan. All rights reserved. |
| 23 |
Possible neutron and proton halo structure in the isobaric analog states of A=12 nuclei |
Demyanova, A.S., Starastsin, V.I., Danilov, A.N., Burtebaev, N., Janseitov, D, et al. |
2020 |
Physical Review C, 2020, 102(5), 054612, Q2 |
The differential cross sections of the B11(He3,d)C12 reaction leading to formation of the 0+ ground state and the 15.11-MeV 1 +, 16.57-MeV 2-, and 17.23-MeV 1- excited states of C12 are measured at Elab=25 MeV. The analysis of the data is carried out within the coupled-reaction-channels method for the direct proton transfer to the bound and unbound states. The rms radii of the last proton in all states studied are determined. A comparison of the rms radii of the B12, C12, and N12 nuclei in the isobaric analog states (IASs) with isospin T=1 determined by different methods allows us to arrive at a conclusion that these nuclei in the 1- excited states at Ex=2.62, 17.23, and 1.80 MeV, respectively, possess one-nucleon (neutron or proton) halo structure. The enlarged radii and a large probability of the last neutron to be outside of the range of the interaction potential are also found for the 2- states of B12, C12, and N12 at Ex=1.67, 16.57, and 1.19 MeV, respectively. These IASs also can be regarded as candidates for states with one-nucleon (neutron or proton) halo. |