Pub Date : 2020-01-31DOI: 10.33581/2520-2243-2020-1-95-104
I. Bruchkouski
The first measurement results of the vertical profiles of nitrogen dioxide over Minsk employing the Multi-axis recorder of spectra MARS-B and analysis of the obtained spatio-temporal series for 2017 is presented. The vertical profiles of nitrogen dioxide have been retrieved in spectral region 338–370 nm by combining the Multi-axis Differential Optical Absorption Spectroscopy method and PriAM algorithm for inverse problem solving during daylight. A comparative analysis of the measurement results has been carried out. The classification by dividing the obtained variety of registered nitrogen dioxide profiles into six groups has been presented. Obtained time series of surface layer nitrogen dioxide concentrations as well as nitrogen dioxide total columns have been presented, their statistics have been analyzed, and comparisons with the level of the maximum permissible concentration of nitrogen dioxide for a human have been performed. The values of near-surface concentrations have been compared with the impact gas analyzer data by monitoring network of the Belhydrometcentre (post No. 11), the analysis of the obtained data rejects the hypothesis of their statistical relationship on the scale of a 1-month time series.
{"title":"First tropospheric measurements of the vertical profle of nitrogen dioxide concentration in Minsk","authors":"I. Bruchkouski","doi":"10.33581/2520-2243-2020-1-95-104","DOIUrl":"https://doi.org/10.33581/2520-2243-2020-1-95-104","url":null,"abstract":"The first measurement results of the vertical profiles of nitrogen dioxide over Minsk employing the Multi-axis recorder of spectra MARS-B and analysis of the obtained spatio-temporal series for 2017 is presented. The vertical profiles of nitrogen dioxide have been retrieved in spectral region 338–370 nm by combining the Multi-axis Differential Optical Absorption Spectroscopy method and PriAM algorithm for inverse problem solving during daylight. A comparative analysis of the measurement results has been carried out. The classification by dividing the obtained variety of registered nitrogen dioxide profiles into six groups has been presented. Obtained time series of surface layer nitrogen dioxide concentrations as well as nitrogen dioxide total columns have been presented, their statistics have been analyzed, and comparisons with the level of the maximum permissible concentration of nitrogen dioxide for a human have been performed. The values of near-surface concentrations have been compared with the impact gas analyzer data by monitoring network of the Belhydrometcentre (post No. 11), the analysis of the obtained data rejects the hypothesis of their statistical relationship on the scale of a 1-month time series.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72916433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-27DOI: 10.33581/2520-2243-2020-1-4-15
A. P. Mikitchuk, K. V. Kozadaev
The work is devoted to the experimental study of the microstructural and morphological properties of nanostructures as part of a prototype of fiber-optic photoacoustic transducer. The transducer has been created to confirm the theoretical investigations previously obtained by the authors during the study the conditions of the most effective photoacoustic gene ration. To solve the main problem that arises when creating photoacoustic transducers, namely reducing the thickness of the absorbing layer, we used a nanostructure based on a monolayer of silver nanoparticles with size gamma-distribution, the average diameter of 35 nm with RMS-size of 12 nm. The method of simultaneous measuring both efficiency of photoacoustic conversion and frequency response of a photoacoustic transducer is proposed for the first time. The method allows experimental investigation of transduces output parameters versus the modulation mode of the optical signal. The proposed method is based on the usage of the main measurement channel for irradiating the photoacoustic transducer and a reference channel based on fiber optical coupler and photodiode. The experiment shows the reliable generation of ultrasound at frequencies of 10 –18 MHz with a prototype of photoacoustic transducer. During one hour irradiation, degradation of two-dimensional surface nanostructures has not been observed. This allows such type of photoacoustic transducer to be used as part of a new generation of technical diagnostics systems.
{"title":"Characteristics of fiber-optic photoacoustic transducers with monolayer of metal nanoparticles for systems of technical diagnostics","authors":"A. P. Mikitchuk, K. V. Kozadaev","doi":"10.33581/2520-2243-2020-1-4-15","DOIUrl":"https://doi.org/10.33581/2520-2243-2020-1-4-15","url":null,"abstract":"The work is devoted to the experimental study of the microstructural and morphological properties of nanostructures as part of a prototype of fiber-optic photoacoustic transducer. The transducer has been created to confirm the theoretical investigations previously obtained by the authors during the study the conditions of the most effective photoacoustic gene ration. To solve the main problem that arises when creating photoacoustic transducers, namely reducing the thickness of the absorbing layer, we used a nanostructure based on a monolayer of silver nanoparticles with size gamma-distribution, the average diameter of 35 nm with RMS-size of 12 nm. The method of simultaneous measuring both efficiency of photoacoustic conversion and frequency response of a photoacoustic transducer is proposed for the first time. The method allows experimental investigation of transduces output parameters versus the modulation mode of the optical signal. The proposed method is based on the usage of the main measurement channel for irradiating the photoacoustic transducer and a reference channel based on fiber optical coupler and photodiode. The experiment shows the reliable generation of ultrasound at frequencies of 10 –18 MHz with a prototype of photoacoustic transducer. During one hour irradiation, degradation of two-dimensional surface nanostructures has not been observed. This allows such type of photoacoustic transducer to be used as part of a new generation of technical diagnostics systems.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74247750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-30DOI: 10.33581/2520-2243-2019-3-73-80
G. Tolstolutskaya, M. Tikhonovsky, V. Voyevodin, A. V. Nikitin, Aleksander S. Tortika, R. Vasilenko
In the present paper processes of sputtering and surface modification of commercial and experimental FeCrAl composites alloyed with yttrium, molybdenum and zirconium were investigated. Using a field-emission scanning electron microscope, it was shown that under the influence of low-energy (500 eV) hydrogen plasma with a flux about 3.2 ⋅ 1020 m–2 ⋅ s–1 and fluence 4 ⋅ 1024 m–2 at Troom, surface morphology develops due to the formation of grooves along grain boundaries, macro- and microcracks, as well as intragranular pits due to the sputtering of precipitates. Determination of the composition of precipitates by an energy dispersive X-ray spectrometer allowed to establish that aluminum oxide is preferentially distributed in the grains of FeCrAl-based alloys, and yttrium oxides are localized along grain boundaries. Results of erosion studies indicated that the sputtering yields for hydrogen on all alloys are 1.05– 0.38 at./ion and doesn’t exceed those for published data for pure iron and chromium. For experimental alloys doped with yttrium and molybdenum found that the obtained sputtering coefficients were in several times lower than for steel SS304 and only one and a half times higher compared to tungsten.
{"title":"Surface modification and sputtering of FeCrAl alloys exposed to low-energy hydrogen plasmas","authors":"G. Tolstolutskaya, M. Tikhonovsky, V. Voyevodin, A. V. Nikitin, Aleksander S. Tortika, R. Vasilenko","doi":"10.33581/2520-2243-2019-3-73-80","DOIUrl":"https://doi.org/10.33581/2520-2243-2019-3-73-80","url":null,"abstract":"In the present paper processes of sputtering and surface modification of commercial and experimental FeCrAl composites alloyed with yttrium, molybdenum and zirconium were investigated. Using a field-emission scanning electron microscope, it was shown that under the influence of low-energy (500 eV) hydrogen plasma with a flux about 3.2 ⋅ 1020 m–2 ⋅ s–1 and fluence 4 ⋅ 1024 m–2 at Troom, surface morphology develops due to the formation of grooves along grain boundaries, macro- and microcracks, as well as intragranular pits due to the sputtering of precipitates. Determination of the composition of precipitates by an energy dispersive X-ray spectrometer allowed to establish that aluminum oxide is preferentially distributed in the grains of FeCrAl-based alloys, and yttrium oxides are localized along grain boundaries. Results of erosion studies indicated that the sputtering yields for hydrogen on all alloys are 1.05– 0.38 at./ion and doesn’t exceed those for published data for pure iron and chromium. For experimental alloys doped with yttrium and molybdenum found that the obtained sputtering coefficients were in several times lower than for steel SS304 and only one and a half times higher compared to tungsten.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"392 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87702163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-30DOI: 10.33581/2520-2243-2019-3-68-72
A. V. Giro, Y. M. Pokotilo, A. N. Petukh
Energy spectrum of radiation defect levels in n-type epitaxial silicon irradiated with 300 keV hydrogen ions was studied by DLTS (deep level transient spectroscopy) method. The increase in the amplitude of DLTS peak with the increase in the temperature of its registration was found. This indicates the formation of areas of defects accumulation with displacement density lower initial level of doping. After exposure of irradiated samples at room temperature for several months, these areas decay with isolated point A-, E-centers and hydrogen defects with an Ec – 0.31 eV level formation. It is shown that complexes with an Ec – 0.31 eV level are formed by attaching hydrogen atoms to A-center. At Т > 150 °С, this defect begins to anneal, and at the same time A-center concentration is increased.
{"title":"Formation and annealing of radiation defects in silicon, implanted with hydrogen ions","authors":"A. V. Giro, Y. M. Pokotilo, A. N. Petukh","doi":"10.33581/2520-2243-2019-3-68-72","DOIUrl":"https://doi.org/10.33581/2520-2243-2019-3-68-72","url":null,"abstract":"Energy spectrum of radiation defect levels in n-type epitaxial silicon irradiated with 300 keV hydrogen ions was studied by DLTS (deep level transient spectroscopy) method. The increase in the amplitude of DLTS peak with the increase in the temperature of its registration was found. This indicates the formation of areas of defects accumulation with displacement density lower initial level of doping. After exposure of irradiated samples at room temperature for several months, these areas decay with isolated point A-, E-centers and hydrogen defects with an Ec – 0.31 eV level formation. It is shown that complexes with an Ec – 0.31 eV level are formed by attaching hydrogen atoms to A-center. At Т > 150 °С, this defect begins to anneal, and at the same time A-center concentration is increased.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77275513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-30DOI: 10.33581/2520-2243-2019-3-61-67
V. Dorosinets, V. A. Borisov
Experimental studies of the temperature dependence of the resistance and magnetoresistance of the composite metal-carbon samples C(Co), which show the effect of weak localization, have been carried out. The magnetoresistance at a temperature T = 2.2 K is alternating, which is explained by the spin-orbit interaction. Analysis of the magnetoresistance curves made it possible to calculate the values of the parameters characterizing the phase loss time in inelastic scattering and the spin-orbit interaction time. For the parameter characterizing the elastic scattering time, the minimum value was estimated.
{"title":"Determination of microscopical parameters of heterogeneous carbon materials","authors":"V. Dorosinets, V. A. Borisov","doi":"10.33581/2520-2243-2019-3-61-67","DOIUrl":"https://doi.org/10.33581/2520-2243-2019-3-61-67","url":null,"abstract":"Experimental studies of the temperature dependence of the resistance and magnetoresistance of the composite metal-carbon samples C(Co), which show the effect of weak localization, have been carried out. The magnetoresistance at a temperature T = 2.2 K is alternating, which is explained by the spin-orbit interaction. Analysis of the magnetoresistance curves made it possible to calculate the values of the parameters characterizing the phase loss time in inelastic scattering and the spin-orbit interaction time. For the parameter characterizing the elastic scattering time, the minimum value was estimated.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88088728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-30DOI: 10.33581/2520-2243-2019-3-51-60
V. M. Bychkov, Yaroslav I. Didkovsky, M. N. Kovalenko, A. Min’ko, Mikhail R. Pasliadovich, Sergei N. Sharashkin, Vera M. Yakavets
This work presents the metrological and operational characteristics of the multichannel vacuum atomic-emission spectrometer for educational and industrial laboratories with a MS-200UN spark generator. The spectrometer uses an original optical scheme consisting of two polychromators: the first polychromator is designed to work in the field of vacuum ultraviolet at the wavelength range from 170 to 290 nm; the second polychromator covers the wavelength range from 290 to 410 nm. The multielement semiconductor photodetectors with remote shielding windows offer fast recording of spectra in the vacuum ultraviolet range for simultaneous evaluation of the concentrations of several chemical elements in the samples under study. It is demonstrated that metrological characteristics of the atomic-emission vacuum spectrometer with a MS-200UN spark generator for educational and industrial laboratories meet the requirements of the normative documents standardizing analysis of metals and alloys. The designed spectrometer may be used in educational process and during routine analyses at laboratories of industrial enterprises and other organizations.
{"title":"Metrological and operational characteristics of the multichannel vacuum atomic-emission spectrometer for educational and industrial laboratories with a MS-200UN spark generator","authors":"V. M. Bychkov, Yaroslav I. Didkovsky, M. N. Kovalenko, A. Min’ko, Mikhail R. Pasliadovich, Sergei N. Sharashkin, Vera M. Yakavets","doi":"10.33581/2520-2243-2019-3-51-60","DOIUrl":"https://doi.org/10.33581/2520-2243-2019-3-51-60","url":null,"abstract":"This work presents the metrological and operational characteristics of the multichannel vacuum atomic-emission spectrometer for educational and industrial laboratories with a MS-200UN spark generator. The spectrometer uses an original optical scheme consisting of two polychromators: the first polychromator is designed to work in the field of vacuum ultraviolet at the wavelength range from 170 to 290 nm; the second polychromator covers the wavelength range from 290 to 410 nm. The multielement semiconductor photodetectors with remote shielding windows offer fast recording of spectra in the vacuum ultraviolet range for simultaneous evaluation of the concentrations of several chemical elements in the samples under study. It is demonstrated that metrological characteristics of the atomic-emission vacuum spectrometer with a MS-200UN spark generator for educational and industrial laboratories meet the requirements of the normative documents standardizing analysis of metals and alloys. The designed spectrometer may be used in educational process and during routine analyses at laboratories of industrial enterprises and other organizations.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"142 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78494050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-30DOI: 10.33581/2520-2243-2019-3-12-21
L. Burov, A. Gorbatsevich, Pavel M. Labatsevich
Based on statistical modeling, a numerical analysis of the effects exerted by different factors (fluctuations of the spontaneous emission intensity, nonequilibrium carrier concentration, injection current density) on the statistical characteristics of radiation at the output of surface emitting semiconductor lasers in the region of polarization instability has been performed. In this region the effect of fluctuations is maximal, offering the possibility for substantiated conclusions about relative effects of the parameters. In a theory of semiconductor lasers it is thought that the intensity fluctuations of spontaneous emission represent the dominant source of fluctuations, whereas all other sources may be neglected. As demonstra ted by the results of conducted statistical modeling, this statement is too rigorous; moreover, such a source is not dominant. Taking into consideration fluctuations of the carrier concentration, which result in fluctuations of the amplification factor, we can derive a complete set of the relationships observed experimentally. This result cannot be associated with features our model because in our theory spontaneous emission is a significant factor. If the influence of spontaneous emission would be the dominant factor, it would affect the simulation results. The obtained data make it possible to doubt the key role of the spontaneous emission intensity fluctuations in the process of statistical characteristics formation for the output radiation and to take into account fluctuations of the nonequilibrium carrier concentration.
{"title":"The influence various sources of fluctuation on the statistical parameters of the vertical cavity surface emitting lasers output radiation","authors":"L. Burov, A. Gorbatsevich, Pavel M. Labatsevich","doi":"10.33581/2520-2243-2019-3-12-21","DOIUrl":"https://doi.org/10.33581/2520-2243-2019-3-12-21","url":null,"abstract":"Based on statistical modeling, a numerical analysis of the effects exerted by different factors (fluctuations of the spontaneous emission intensity, nonequilibrium carrier concentration, injection current density) on the statistical characteristics of radiation at the output of surface emitting semiconductor lasers in the region of polarization instability has been performed. In this region the effect of fluctuations is maximal, offering the possibility for substantiated conclusions about relative effects of the parameters. In a theory of semiconductor lasers it is thought that the intensity fluctuations of spontaneous emission represent the dominant source of fluctuations, whereas all other sources may be neglected. As demonstra ted by the results of conducted statistical modeling, this statement is too rigorous; moreover, such a source is not dominant. Taking into consideration fluctuations of the carrier concentration, which result in fluctuations of the amplification factor, we can derive a complete set of the relationships observed experimentally. This result cannot be associated with features our model because in our theory spontaneous emission is a significant factor. If the influence of spontaneous emission would be the dominant factor, it would affect the simulation results. The obtained data make it possible to doubt the key role of the spontaneous emission intensity fluctuations in the process of statistical characteristics formation for the output radiation and to take into account fluctuations of the nonequilibrium carrier concentration.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"81 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90482582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-30DOI: 10.33581/2520-2243-2019-3-41-50
I. A. Shershan, T. Shishkina
In this paper the analysis of W-boson production process in high-energy electron-photon collisions as a tool to search for deviations from the Standard Model is considered. In particular, a set of extended gauge models, including anomalous multi-boson interactions, are discussed as a promising way for «new physics» study. A numerical analysis of the total cross sections of the processes was carried out. The lowest order radiative corrections in the soft-photon approximation within the Standard Model are taken into account. Calculations beyond the Standard Model was performed, the kinematic features of the cross sections were identified. The restrictions on the anomalous triple gauge boson coupling constants were analyzed and the kinematic areas to the search for their manifestations were obtained during the experiments at the International Linear Collider. The paper shows that the search for «new physics» effects based on electron-photon collisions around the W-boson production peak is the maximal promising. It was also shown that future experiments at high luminosity linear colliders will significantly clarify the constraints on anomalous gauge coupling constants.
{"title":"W-boson production in the high energy electron-photon collisions","authors":"I. A. Shershan, T. Shishkina","doi":"10.33581/2520-2243-2019-3-41-50","DOIUrl":"https://doi.org/10.33581/2520-2243-2019-3-41-50","url":null,"abstract":"In this paper the analysis of W-boson production process in high-energy electron-photon collisions as a tool to search for deviations from the Standard Model is considered. In particular, a set of extended gauge models, including anomalous multi-boson interactions, are discussed as a promising way for «new physics» study. A numerical analysis of the total cross sections of the processes was carried out. The lowest order radiative corrections in the soft-photon approximation within the Standard Model are taken into account. Calculations beyond the Standard Model was performed, the kinematic features of the cross sections were identified. The restrictions on the anomalous triple gauge boson coupling constants were analyzed and the kinematic areas to the search for their manifestations were obtained during the experiments at the International Linear Collider. The paper shows that the search for «new physics» effects based on electron-photon collisions around the W-boson production peak is the maximal promising. It was also shown that future experiments at high luminosity linear colliders will significantly clarify the constraints on anomalous gauge coupling constants.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"117 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79385239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-30DOI: 10.33581/2520-2243-2019-3-81-91
Y. Groda, Vera Grishina, A. Ciach, V. Vikhrenko
The lattice system with competing interactions (repulsive between nearest neighbors and attractive between nextnext-nearest neighbors) on a triangular lattice is studied. The possibility of existence of two types of ordered phases in the system is established. The initial lattice was splitted into a system of four identical triangular sublattices to describe the ordered phases. The geometric order parameter of the system is introduced. Using the order parameter, the critical value of the interaction parameter is determined and the phase diagram of the system is constructed. The dependence of the critical parameter of the model on the ratio of intensity of competing interactions is investigated. The simulation data for the chemical potential are compared with the results of the quasichemical approximation. It is shown that the quasichemical approximation results in an adequate assessment of the equilibrium properties of the model in the range of its applicability.
{"title":"Phase diagram of the lattice fluid with SRLA-potential on the plane triangular lattice","authors":"Y. Groda, Vera Grishina, A. Ciach, V. Vikhrenko","doi":"10.33581/2520-2243-2019-3-81-91","DOIUrl":"https://doi.org/10.33581/2520-2243-2019-3-81-91","url":null,"abstract":"The lattice system with competing interactions (repulsive between nearest neighbors and attractive between nextnext-nearest neighbors) on a triangular lattice is studied. The possibility of existence of two types of ordered phases in the system is established. The initial lattice was splitted into a system of four identical triangular sublattices to describe the ordered phases. The geometric order parameter of the system is introduced. Using the order parameter, the critical value of the interaction parameter is determined and the phase diagram of the system is constructed. The dependence of the critical parameter of the model on the ratio of intensity of competing interactions is investigated. The simulation data for the chemical potential are compared with the results of the quasichemical approximation. It is shown that the quasichemical approximation results in an adequate assessment of the equilibrium properties of the model in the range of its applicability.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81145452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-30DOI: 10.33581/2520-2243-2019-3-31-40
Uladzimir Khasianevich, T. Shishkina
Numerical results for the total cross section, polarization asymmetry, as well as forward-backward asymmetry are presented. Calculations were carried out for longitudinal polarization of the initial electron-positron beams, as well as for the unpolarized case in the one-loop approximation for the standard electroweak Glashow – Weinberg – Salam model without considering quark fields. As a renormalization scheme, we used a non-minimal on-shell scheme with simultaneous renorma lization of the fields. In addition to considering the radiation of soft photons, numerical analysis of hard bremsstrahlung was performed. Analysis of the effect of the cut-off parameters of the phase region of the three-particle final state was made, which are the acollinearity angle between the final leptons, the detecting threshold energies of the final particles, and the radiation energy of the soft photons. An algorithm for obtaining ultraviolet convergent expressions is described. The calculations were carried out in the formalism of the Passarino – Veltman functions in the light-lepton approximation.
{"title":"Electroweak one-loop corrections to the process of fermion pair production in electron-positron annihilation","authors":"Uladzimir Khasianevich, T. Shishkina","doi":"10.33581/2520-2243-2019-3-31-40","DOIUrl":"https://doi.org/10.33581/2520-2243-2019-3-31-40","url":null,"abstract":"Numerical results for the total cross section, polarization asymmetry, as well as forward-backward asymmetry are presented. Calculations were carried out for longitudinal polarization of the initial electron-positron beams, as well as for the unpolarized case in the one-loop approximation for the standard electroweak Glashow – Weinberg – Salam model without considering quark fields. As a renormalization scheme, we used a non-minimal on-shell scheme with simultaneous renorma lization of the fields. In addition to considering the radiation of soft photons, numerical analysis of hard bremsstrahlung was performed. Analysis of the effect of the cut-off parameters of the phase region of the three-particle final state was made, which are the acollinearity angle between the final leptons, the detecting threshold energies of the final particles, and the radiation energy of the soft photons. An algorithm for obtaining ultraviolet convergent expressions is described. The calculations were carried out in the formalism of the Passarino – Veltman functions in the light-lepton approximation.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79865280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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