Pub Date : 2020-01-01DOI: 10.1142/s2010194520600137
Sh.S. Zeinalov, P. Sedyshev, O. Sidorova, V. Shvetsov
In this paper, we report recent results obtained in the development of digital pulse processing mathematics for prompt fission neutron (PFN) investigations using a twin ionization chamber (TIC) along with a fast neutron time-of-flight detector (ND). Due to some ambiguities in the literature concerning a pulse induction on TIC electrodes by fission fragment (FF) ionization, we first presented a detailed mathematical analysis of FF signal formation on the TIC anode. The analysis was done using the Shockley–Ramo theorem, which gives the relation between charged particle motion between TIC electrodes and the so-called weighting potential. The weighting potential was calculated by direct numerical solution of the Laplace equation (neglecting space charge) for the TIC geometry and ionization caused by FFs. Formulae for GI correction and digital pulse processing algorithms for PFN time-of-flight measurements and pulse shape analysis are presented and used in experiments for PFN investigations of two reactions, [Formula: see text]U(n[Formula: see text],f) and [Formula: see text]Cf(sf). Results of the measurements were compared to literature data to demonstrate the feasibility of the new developed techniques. These results were necessary for the development of a new PFN investigation facility consisting of a position sensitive fission fragment detector combined with 32 liquid scintillation neutron detectors.
{"title":"Nuclear fission investigation with twin ionization chamber","authors":"Sh.S. Zeinalov, P. Sedyshev, O. Sidorova, V. Shvetsov","doi":"10.1142/s2010194520600137","DOIUrl":"https://doi.org/10.1142/s2010194520600137","url":null,"abstract":"In this paper, we report recent results obtained in the development of digital pulse processing mathematics for prompt fission neutron (PFN) investigations using a twin ionization chamber (TIC) along with a fast neutron time-of-flight detector (ND). Due to some ambiguities in the literature concerning a pulse induction on TIC electrodes by fission fragment (FF) ionization, we first presented a detailed mathematical analysis of FF signal formation on the TIC anode. The analysis was done using the Shockley–Ramo theorem, which gives the relation between charged particle motion between TIC electrodes and the so-called weighting potential. The weighting potential was calculated by direct numerical solution of the Laplace equation (neglecting space charge) for the TIC geometry and ionization caused by FFs. Formulae for GI correction and digital pulse processing algorithms for PFN time-of-flight measurements and pulse shape analysis are presented and used in experiments for PFN investigations of two reactions, [Formula: see text]U(n[Formula: see text],f) and [Formula: see text]Cf(sf). Results of the measurements were compared to literature data to demonstrate the feasibility of the new developed techniques. These results were necessary for the development of a new PFN investigation facility consisting of a position sensitive fission fragment detector combined with 32 liquid scintillation neutron detectors.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83267293","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 : 2019-07-22DOI: 10.1142/S2010194519600206
S. Shaymatov
We investigate the effect of magnetic field on the process of overcharging magnetized Reissner–Nordström black hole. It is well known that a four dimensional charged black hole could be overcharged. Contrary to this, we show that a magnetized charged black hole could not be overcharged beyond threshold value of the magnetic field. This occurs because the magnetic field does not allow for particle to reach black hole horizon. Thus magnetic field beyond its threshold value could restore the cosmic censorship conjecture.
{"title":"Magnetized Reissner–Nordström black hole restores cosmic censorship conjecture","authors":"S. Shaymatov","doi":"10.1142/S2010194519600206","DOIUrl":"https://doi.org/10.1142/S2010194519600206","url":null,"abstract":"We investigate the effect of magnetic field on the process of overcharging magnetized Reissner–Nordström black hole. It is well known that a four dimensional charged black hole could be overcharged. Contrary to this, we show that a magnetized charged black hole could not be overcharged beyond threshold value of the magnetic field. This occurs because the magnetic field does not allow for particle to reach black hole horizon. Thus magnetic field beyond its threshold value could restore the cosmic censorship conjecture.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79095349","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 : 2019-07-22DOI: 10.1142/S2010194519600188
B. Ahmedov, B. Turimov, Z. Stuchlík, A. Tursunov
We study in the weak field limit the gravitational lensing by spherically symmetric compact object immersed in an asymptotically uniform magnetic field in the presence of plasma and our approach is based on the medium modified Hamiltonian one. We show that the magnetized plasma in the environment of compact object may lead to split of the Einstein cross, creating additional lensed components. Finally we calculate magnification and time delay related to the individual images.
{"title":"Optical properties of magnetized black hole in plasma","authors":"B. Ahmedov, B. Turimov, Z. Stuchlík, A. Tursunov","doi":"10.1142/S2010194519600188","DOIUrl":"https://doi.org/10.1142/S2010194519600188","url":null,"abstract":"We study in the weak field limit the gravitational lensing by spherically symmetric compact object immersed in an asymptotically uniform magnetic field in the presence of plasma and our approach is based on the medium modified Hamiltonian one. We show that the magnetized plasma in the environment of compact object may lead to split of the Einstein cross, creating additional lensed components. Finally we calculate magnification and time delay related to the individual images.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"55 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78639027","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 : 2019-07-22DOI: 10.1142/S201019451960019X
Rayimbaev Javlon, Turimov Bobur, Palvanov Satimbay
The analytical expression for Goldreich-Julian (GJ) charge density at the polar cap of magnetized neutron star has been obtained in braneworlds for inclined neutron star through solving Maxwell equations and shown that the value of GJ charge density decreases with increasing the value of the brane charge. The analytical expressions for scalar potential and parallel electric field on the region greater than the polar cap region of the neutron star have also been obtained by solving Poisson equation in braneworlds.
{"title":"Plasma magnetosphere of slowly rotating magnetized neutron star in branewold","authors":"Rayimbaev Javlon, Turimov Bobur, Palvanov Satimbay","doi":"10.1142/S201019451960019X","DOIUrl":"https://doi.org/10.1142/S201019451960019X","url":null,"abstract":"The analytical expression for Goldreich-Julian (GJ) charge density at the polar cap of magnetized neutron star has been obtained in braneworlds for inclined neutron star through solving Maxwell equations and shown that the value of GJ charge density decreases with increasing the value of the brane charge. The analytical expressions for scalar potential and parallel electric field on the region greater than the polar cap region of the neutron star have also been obtained by solving Poisson equation in braneworlds.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81021744","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 : 2019-07-22DOI: 10.1142/S2010194519600085
V. Sargsyan, Z. Kanokov, G. Adamian, N. Antonenko
Projectile-nucleus capture by a target nucleus at bombarding energies in the vicinity of the Coulomb barrier is treated with the reduced-density-matrix formalism. The effects of dissipation and fluctuations on the capture process are taken self-consistently into account within the quantum model suggested. The excitation functions for the capture in the reactions [Formula: see text]O, [Formula: see text]F, [Formula: see text]Mg, [Formula: see text]Si, [Formula: see text]S, [Formula: see text]Ca, [Formula: see text]Ti, [Formula: see text]Cr [Formula: see text] [Formula: see text]Pb are calculated and compared with the experimental data.
{"title":"Application of the theory of open quantum systems in nuclear physics","authors":"V. Sargsyan, Z. Kanokov, G. Adamian, N. Antonenko","doi":"10.1142/S2010194519600085","DOIUrl":"https://doi.org/10.1142/S2010194519600085","url":null,"abstract":"Projectile-nucleus capture by a target nucleus at bombarding energies in the vicinity of the Coulomb barrier is treated with the reduced-density-matrix formalism. The effects of dissipation and fluctuations on the capture process are taken self-consistently into account within the quantum model suggested. The excitation functions for the capture in the reactions [Formula: see text]O, [Formula: see text]F, [Formula: see text]Mg, [Formula: see text]Si, [Formula: see text]S, [Formula: see text]Ca, [Formula: see text]Ti, [Formula: see text]Cr [Formula: see text] [Formula: see text]Pb are calculated and compared with the experimental data.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"11 16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84308806","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 : 2019-07-22DOI: 10.1142/s2010194519600176
K. Tursunmakhatov, R. Yarmukhamedov
The results of the analysis of the new experimental astrophysical S factors [Formula: see text] [D. Trezzi et al., Astropart. Phys. 89, 57 (2017)] and those measured earlier [R. G. Robertson et al., Phys. Rev. Lett. 47, 1867 (1981)] for the nuclear-astrophysical [Formula: see text] reaction directly measured at extremely low energies [Formula: see text], which is derived within the modified two-body potential method, are presented. New estimates and their uncertainties have been obtained for values of the asymptotic normalization coefficient for [Formula: see text] and for the direct astrophysical [Formula: see text] factors at Big Bang energies.
新实验天体物理S因子分析结果[公式:见文][D]。Trezzi等人，Astropart。物理学报，89,57(2017)]和之前的测量[R]。G. Robertson et al.，物理学。本文介绍了核天体物理[公式:见文本]在极低能量下直接测量的反应[公式:见文本]，它是在修正的二体势法中推导出来的。对于大爆炸能量的[公式:见文]和直接天体物理[公式:见文]因子的渐近归一化系数的值，已经获得了新的估计和它们的不确定性。
{"title":"Determination of the asymptotic normalization coefficient (nuclear vertex constant) for α + d →6Li from the new direct measured d(α,γ)6Li data and its implication for extrapolating the d(α,γ)6Li astrophysical S factor at Big Bang energies","authors":"K. Tursunmakhatov, R. Yarmukhamedov","doi":"10.1142/s2010194519600176","DOIUrl":"https://doi.org/10.1142/s2010194519600176","url":null,"abstract":"The results of the analysis of the new experimental astrophysical S factors [Formula: see text] [D. Trezzi et al., Astropart. Phys. 89, 57 (2017)] and those measured earlier [R. G. Robertson et al., Phys. Rev. Lett. 47, 1867 (1981)] for the nuclear-astrophysical [Formula: see text] reaction directly measured at extremely low energies [Formula: see text], which is derived within the modified two-body potential method, are presented. New estimates and their uncertainties have been obtained for values of the asymptotic normalization coefficient for [Formula: see text] and for the direct astrophysical [Formula: see text] factors at Big Bang energies.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88690718","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 : 2019-04-01DOI: 10.1142/S2010194519600048
M. Oka, Saori Maeda, Yan-Rui Liu
Charmed dibaryon states with the spin-parity [Formula: see text], and [Formula: see text] are predicted for the two-body [Formula: see text] ([Formula: see text], [Formula: see text], or [Formula: see text]) systems. We employ the complex scaling method for the coupled channel Hamiltonian with the [Formula: see text]-CTNN potentials, which were proposed in our previous study. We find four sharp resonance states near the [Formula: see text] and [Formula: see text] thresholds. From the analysis of the binding energies of partial channel systems, we conclude that these resonance states are Feshbach resonances. We compare the results with the [Formula: see text] resonance states in the heavy quark limit, where the [Formula: see text] and [Formula: see text] thresholds are degenerate, and find that they form two pairs of the heavy-quark doublets in agreement with the heavy quark spin symmetry.
{"title":"Charmed dibaryon resonances in the potential quark model","authors":"M. Oka, Saori Maeda, Yan-Rui Liu","doi":"10.1142/S2010194519600048","DOIUrl":"https://doi.org/10.1142/S2010194519600048","url":null,"abstract":"Charmed dibaryon states with the spin-parity [Formula: see text], and [Formula: see text] are predicted for the two-body [Formula: see text] ([Formula: see text], [Formula: see text], or [Formula: see text]) systems. We employ the complex scaling method for the coupled channel Hamiltonian with the [Formula: see text]-CTNN potentials, which were proposed in our previous study. We find four sharp resonance states near the [Formula: see text] and [Formula: see text] thresholds. From the analysis of the binding energies of partial channel systems, we conclude that these resonance states are Feshbach resonances. We compare the results with the [Formula: see text] resonance states in the heavy quark limit, where the [Formula: see text] and [Formula: see text] thresholds are degenerate, and find that they form two pairs of the heavy-quark doublets in agreement with the heavy quark spin symmetry.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"108 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74648473","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 : 2019-01-01DOI: 10.1142/S2010194519600097
J. Nabi, Muhammad Majid, Muhammad Riaz
The allowed Gamow-Teller (GT) strength distributions and associated weak interaction rates on fp-shell nuclei play crucial role in several astrophysical processes, particularly in nucleosynthesis, stellar evolution and supernova explosions. Results from simulation show that the electron capture (EC) rates on medium-heavy nuclei have a significant impact on decreasing the electron-to-baryon ratio of the stellar matter during the late stages of star formation. In this work we present the computation of allowed charge-changing transitions for odd-A fp-shell nuclei by using the deformed pn-QRPA model. The calculated GT strength distributions are compared with previous calculations (including shell and other QRPA models) and measured charge-changing reaction results. The associated EC rates are computed in stellar environment and are compared with previous theoretical results. It is concluded that our results are in good accordance with measured data. For [Formula: see text]Sc, [Formula: see text]V and [Formula: see text]Co, at high stellar temperatures, our calculated EC rates are bigger than the independent-particle and shell model rates. For [Formula: see text]Mn we generally calculate smaller EC rates than previous calculations. The differences with previous calculations may have consequences for supernovae simulators.
{"title":"Allowed Gamow-Teller strength distributions and stellar electron capture rates on odd-A nuclei","authors":"J. Nabi, Muhammad Majid, Muhammad Riaz","doi":"10.1142/S2010194519600097","DOIUrl":"https://doi.org/10.1142/S2010194519600097","url":null,"abstract":"The allowed Gamow-Teller (GT) strength distributions and associated weak interaction rates on fp-shell nuclei play crucial role in several astrophysical processes, particularly in nucleosynthesis, stellar evolution and supernova explosions. Results from simulation show that the electron capture (EC) rates on medium-heavy nuclei have a significant impact on decreasing the electron-to-baryon ratio of the stellar matter during the late stages of star formation. In this work we present the computation of allowed charge-changing transitions for odd-A fp-shell nuclei by using the deformed pn-QRPA model. The calculated GT strength distributions are compared with previous calculations (including shell and other QRPA models) and measured charge-changing reaction results. The associated EC rates are computed in stellar environment and are compared with previous theoretical results. It is concluded that our results are in good accordance with measured data. For [Formula: see text]Sc, [Formula: see text]V and [Formula: see text]Co, at high stellar temperatures, our calculated EC rates are bigger than the independent-particle and shell model rates. For [Formula: see text]Mn we generally calculate smaller EC rates than previous calculations. The differences with previous calculations may have consequences for supernovae simulators.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88615801","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 : 2019-01-01DOI: 10.1142/S2010194519600140
S. A. Turakulov, E. M. Tursunov
The reaction rates of the direct astrophysical capture processes [Formula: see text] and [Formula: see text], as well as the abundance of the [Formula: see text] element are estimated in the framework of a two-body potential model. The estimated [Formula: see text] abundance ratio of [Formula: see text] is in a very good agreement with the recent measurement [Formula: see text] of the LUNA collaboration.
{"title":"3He(α,γ)7Be and 3H(α,γ)7Li reaction rates and implication for Big Bang nucleosynthesis in the potential model","authors":"S. A. Turakulov, E. M. Tursunov","doi":"10.1142/S2010194519600140","DOIUrl":"https://doi.org/10.1142/S2010194519600140","url":null,"abstract":"The reaction rates of the direct astrophysical capture processes [Formula: see text] and [Formula: see text], as well as the abundance of the [Formula: see text] element are estimated in the framework of a two-body potential model. The estimated [Formula: see text] abundance ratio of [Formula: see text] is in a very good agreement with the recent measurement [Formula: see text] of the LUNA collaboration.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86997695","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 : 2019-01-01DOI: 10.1142/S2010194519600073
U. Yakhshiev
We discuss the properties of nucleons in nuclear matter and the properties of nucleonic systems in the framework of an in-medium modified Skyrme Lagrangian. The modification is achieved by introducing the medium functionals into the original Skyrme Model Lagrangian in free space[Formula: see text]. The parameters of the medium functionals are related to the low density phenomenology (i.e. to the pionic atoms3) from the one side and to the properties of nuclear matter at the saturation density [Formula: see text] from the other side. After fitting the parameters of the model, the extrapolations into the low density and high density regions showed that the model can successfully describe the Equations of State (EoS) of nuclear matter in the wide range of densities including the high critical densities existing in the interiors of neutron stars.
{"title":"From nucleons to nuclei (chiral soliton approach)","authors":"U. Yakhshiev","doi":"10.1142/S2010194519600073","DOIUrl":"https://doi.org/10.1142/S2010194519600073","url":null,"abstract":"We discuss the properties of nucleons in nuclear matter and the properties of nucleonic systems in the framework of an in-medium modified Skyrme Lagrangian. The modification is achieved by introducing the medium functionals into the original Skyrme Model Lagrangian in free space[Formula: see text]. The parameters of the medium functionals are related to the low density phenomenology (i.e. to the pionic atoms3) from the one side and to the properties of nuclear matter at the saturation density [Formula: see text] from the other side. After fitting the parameters of the model, the extrapolations into the low density and high density regions showed that the model can successfully describe the Equations of State (EoS) of nuclear matter in the wide range of densities including the high critical densities existing in the interiors of neutron stars.","PeriodicalId":92221,"journal":{"name":"International journal of modern physics. Conference series","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90175242","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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