α decay energies of 323 heavy nuclei with Z ≥82 are evaluated with a macroscopic-microscopic model. In this model, the macroscopic part is treated by the continuous medium model and the microscopic part consists of ...α decay energies of 323 heavy nuclei with Z ≥82 are evaluated with a macroscopic-microscopic model. In this model, the macroscopic part is treated by the continuous medium model and the microscopic part consists of shell and pairing corrections based on the Nilsson potential. α decay half-lives are calculated bY Viola-Seaborg formula. The results of α decay energies and half-lives are compared with experimental values and satisfactory agreement is found. The recoiling effect of the daughter nucleus on α decay half-life is also discussed.展开更多
α decay half-lives of some new synthesized superheavy elements, possibly synthesized superheavy elements and decay products are calculated theoretically within the WKB approximation by using microscopic α-nucleus in...α decay half-lives of some new synthesized superheavy elements, possibly synthesized superheavy elements and decay products are calculated theoretically within the WKB approximation by using microscopic α-nucleus interaction potentials. These nuclear potentials between the α particle and daughter nuclei are obtained by using the double folding integral of the matter density distribution of the α particle and daughter nuclei with a density-dependent effective nucleon-nucleon interaction, in which the zero-range exchange term is supplemented. The calculated α decay half-lives are compared with those of the different models and experimental data. It is shown that the present calculation successfully provides the half-lives of the observed decays for some new superheavy elements and therefore gives reliable predictions for α decay of possibly synthesized superheavy elements in future experiments.展开更多
The present work is a continuation of our previous paper[J.-G. Deng, et al., Chin. Phys. C, 41：124109 （2017）]. In the present work, the α decay half-life of the unknown nucleus 296Og is predicted within the two-po...The present work is a continuation of our previous paper[J.-G. Deng, et al., Chin. Phys. C, 41：124109 （2017）]. In the present work, the α decay half-life of the unknown nucleus 296Og is predicted within the two-potential approach and the hindrance factors of all 20 even-even nuclei in the same region as 296Og, i.e. proton number 82 〈 Z 〈 126 and neutron number 152 〈 N 〈 184, from 250Cm to 294Og, are extracted. The prediction is 1.09 ms within a factor of 5.12. In addition, based on the latest experimental data, a new set of parameters of α decay hindrance factors for the even-even nuclei in this region, considering the shell effect and proton-neutron interaction, are obtained.展开更多
The α decay half-life of the unknown nucleus 297Og is predicted within the two-potential approach, andα preformation probabilities of 64 odd-A nuclei in the region of proton numbers 82 〈 Z 〈 126 and neutron number...The α decay half-life of the unknown nucleus 297Og is predicted within the two-potential approach, andα preformation probabilities of 64 odd-A nuclei in the region of proton numbers 82 〈 Z 〈 126 and neutron numbers 152 〈 N 〈 184, from 251Cf to 295Og, are extracted. In addition, based on the latest experimental data, a new set of parameters for α preformation probabilities considering the shell effect and proton-neutron interaction are obtained.The predicted α decay half-life of 297Og is 0.16 ms within a factor of 4.97. The predicted spin and parity of the ground states for 269Sg,285Fl and 293Lv are 3/2＋, 3/2＋ and 5/2＋, respectively.展开更多
The shell correction effects on the α decay properties of heavy and superheavy nuclei have been studied in a macroscopic-microscopic manner. The macroscopic part is constructed from the generalized liquid drop model...The shell correction effects on the α decay properties of heavy and superheavy nuclei have been studied in a macroscopic-microscopic manner. The macroscopic part is constructed from the generalized liquid drop model（GLDM）, whereas the microscopic part, namely, the shell correction energy, brings about certain effects on the potential barriers and half-lives under a WKB approximation, which is emphasized in this work. The results show that the shell effects play a significant role in the estimation of the α decay half-lives within the actinide region.Predictions of the α decay half-lives are then generated for superheavy nuclei, which will provide useful information for future experiments.展开更多
α decay half-lives are calculated using the Qα values obtained by Semi-empirical Shell Model in the framework of the Unified Fission Model （UFM） with the Coulomb repulsion, nuclear attraction due to proximity pote...α decay half-lives are calculated using the Qα values obtained by Semi-empirical Shell Model in the framework of the Unified Fission Model （UFM） with the Coulomb repulsion, nuclear attraction due to proximity potential, and rotational energy due to angular momentum transfer of a particle. In addition, the calculated and experimental half-lives of 425 nuclei are compared to check the validity of the model applied on α decay. The calculated half-lives of decay are in good agreement with the experimental data. Finally, some useful predications on the α decay half-lives are provided for future experiments.展开更多
In this contribution I would like to review briefly our recent studies on nuclear α formation probabilities in heavy nuclei and their indication on the underlying structure of the nuclei involved.In particular, I wil...In this contribution I would like to review briefly our recent studies on nuclear α formation probabilities in heavy nuclei and their indication on the underlying structure of the nuclei involved.In particular, I will show that the empirical α-formation probabilities, which can be extracted from experimental half-lives, exhibit a rather smooth function with changing proton or neutron numbers. This allows us to distinguish the role played by pairing collectivity in the clustering process. The sudden hindrance of the clustering of the nucleons around the N = 126 shell closure is due to the fact that the configuration space does not allow a proper manifestation of the pairing collectivity. The influence of the Z = 82 shell closure on the α formation properties will also be discussed. Moreover, we have evaluated the α-decay fine structure to excited 0+states in Hg and Rn isotopes as well as the α-decay from the excited 0+states in the mother nucleus. It is thus found that the α decay is sensitive to the mixture of configurations corresponding to different nuclear shapes.展开更多
Two recently observed ^293Lv （Z = 116） α-decay chains [Eur. Phys. J. A 48, 62 （2012）] are investigated in the framework of covariant density functional theory with PC-PK1, where the pairing correlations are treat...Two recently observed ^293Lv （Z = 116） α-decay chains [Eur. Phys. J. A 48, 62 （2012）] are investigated in the framework of covariant density functional theory with PC-PK1, where the pairing correlations are treated by the Bardeen-Cooper-Schrieffer method with a density-independent zerorange force. From the calculated potential energy curves, it is found that two minima always occur, with one having an almost spherical shape and the other exhibiting a large deformed prolate shape. Originating from the ground state and the shape-isomeric state of ^293Lv, the two observed a-decay chains are constructed and the calculated Qα values are found to be in good agreement with the data.展开更多
The α-preformation probability is directly deduced from experimental α decay energies and half-lives in an analytical way without any modified parameters. Several other model-deduced results, are used to compare wit...The α-preformation probability is directly deduced from experimental α decay energies and half-lives in an analytical way without any modified parameters. Several other model-deduced results, are used to compare with that of the present study. The key role played by the shell effects in the v-preformation process is indicated in all these cases. In detail, the α-preformation factors of different theoretical extractions are found to have similar behavior for one given isotopic chain, implying the model-independent varying trend of the preformation probability of α particle. In addition, the formation probability of heavier particle in cluster radioactivity is also obtained, and this confirms the relationship between the cluster preformation factor and the product of the cluster and daughter proton numbers.展开更多
The study of cluster structures in light nuclei is extending to the heavy nuclei in these years. As for the stable N = Z nuclei, from the lighter 8Be, 12C nuclei to the heavier 20Ne and even the 40Ca and 44Ti medium n...The study of cluster structures in light nuclei is extending to the heavy nuclei in these years. As for the stable N = Z nuclei, from the lighter 8Be, 12C nuclei to the heavier 20Ne and even the 40Ca and 44Ti medium nuclei, the a cluster structures have been well studied and confirmed. In heavy nuclei, due to the dominated mean field, the existence of α cluster structure is not clear as light nuclei but some clues were found for indicating the core＋ α cluster structure in some nuclei, in particular, the 208 pb＋α structure in 212Po. We review some recent progress about the theoretical and experimental explorations of the a-clustering effects in heavy nuclei. We also discuss the possible a cluster structure of heavy nuclei from the view of a decay.展开更多
In this paper, based on the two-potential approach combining with the isospin dependent nuclear potential, we systematically compare the α preformation probabilities of odd-A nuclei between nuclear isomeric states an...In this paper, based on the two-potential approach combining with the isospin dependent nuclear potential, we systematically compare the α preformation probabilities of odd-A nuclei between nuclear isomeric states and ground states. The results indicate that during the process of α particle preforming, the low lying nuclear isomeric states are similar to ground states. Meanwhile, in the framework of single nucleon energy level structure, we find that for nuclei with nucleon number below the magic numbers, the α preformation probabilities of high-spin states seem to be larger than low ones. For nuclei with nucleon number above the magic numbers, the α preformation probabilities of isomeric states are larger than those of ground states.展开更多
基金National Natural Science Foundation of China (10475003, 10435010, 10705014, 10575036)Major State BasicResearch Development Program of China (2007CB815000)Knowledge Innovation Project of Chinese Academy of Sciences(KJCX3-SYW-N02, KJCX2-SW-N17)
文摘α decay energies of 323 heavy nuclei with Z ≥82 are evaluated with a macroscopic-microscopic model. In this model, the macroscopic part is treated by the continuous medium model and the microscopic part consists of shell and pairing corrections based on the Nilsson potential. α decay half-lives are calculated bY Viola-Seaborg formula. The results of α decay energies and half-lives are compared with experimental values and satisfactory agreement is found. The recoiling effect of the daughter nucleus on α decay half-life is also discussed.
基金National Natural Science Foundation of China (60572177)
文摘α decay half-lives of some new synthesized superheavy elements, possibly synthesized superheavy elements and decay products are calculated theoretically within the WKB approximation by using microscopic α-nucleus interaction potentials. These nuclear potentials between the α particle and daughter nuclei are obtained by using the double folding integral of the matter density distribution of the α particle and daughter nuclei with a density-dependent effective nucleon-nucleon interaction, in which the zero-range exchange term is supplemented. The calculated α decay half-lives are compared with those of the different models and experimental data. It is shown that the present calculation successfully provides the half-lives of the observed decays for some new superheavy elements and therefore gives reliable predictions for α decay of possibly synthesized superheavy elements in future experiments.
基金Supported by National Natural Science Foundation of China(11205083,11505100)the Construct Program of the Key Discipline in Hunan Province+4 种基金the Research Foundation of Education Bureau of Hunan Province,China(15A159)the Natural Science Foundation of Hunan Province,China(2015JJ3103,2015JJ2121)the Innovation Group of Nuclear and Particle Physics in USCthe Shandong Province Natural Science Foundation,China(ZR2015AQ007)Hunan Provincial Innovation Foundation For Postgraduate(CX2017B536)
文摘The present work is a continuation of our previous paper[J.-G. Deng, et al., Chin. Phys. C, 41：124109 （2017）]. In the present work, the α decay half-life of the unknown nucleus 296Og is predicted within the two-potential approach and the hindrance factors of all 20 even-even nuclei in the same region as 296Og, i.e. proton number 82 〈 Z 〈 126 and neutron number 152 〈 N 〈 184, from 250Cm to 294Og, are extracted. The prediction is 1.09 ms within a factor of 5.12. In addition, based on the latest experimental data, a new set of parameters of α decay hindrance factors for the even-even nuclei in this region, considering the shell effect and proton-neutron interaction, are obtained.
基金Supported by National Natural Science Foundation of China(11205083,11505100)Construct Program of the Key Discipline in Hunan Province,the Research Foundation of Education Bureau of Hunan Province,China(15A159)+2 种基金the Natural Science Foundation of Hunan Province,China(2015JJ3103,2015JJ2121)the Innovation Group of Nuclear and Particle Physics in USC,the Shandong Province Natural Science Foundation,China(ZR2015AQ007)Hunan Provincial Innovation Foundation For Postgraduate(CX2017B536)
文摘The α decay half-life of the unknown nucleus 297Og is predicted within the two-potential approach, andα preformation probabilities of 64 odd-A nuclei in the region of proton numbers 82 〈 Z 〈 126 and neutron numbers 152 〈 N 〈 184, from 251Cf to 295Og, are extracted. In addition, based on the latest experimental data, a new set of parameters for α preformation probabilities considering the shell effect and proton-neutron interaction are obtained.The predicted α decay half-life of 297Og is 0.16 ms within a factor of 4.97. The predicted spin and parity of the ground states for 269Sg,285Fl and 293Lv are 3/2＋, 3/2＋ and 5/2＋, respectively.
基金Supported by National Natural Science Foundation of China(11675066,11475050)the Fundamental Research Funds for the Central Universities(lzujbky-2017-ot04)Feitian Scholar Project of Gansu Province
文摘The shell correction effects on the α decay properties of heavy and superheavy nuclei have been studied in a macroscopic-microscopic manner. The macroscopic part is constructed from the generalized liquid drop model（GLDM）, whereas the microscopic part, namely, the shell correction energy, brings about certain effects on the potential barriers and half-lives under a WKB approximation, which is emphasized in this work. The results show that the shell effects play a significant role in the estimation of the α decay half-lives within the actinide region.Predictions of the α decay half-lives are then generated for superheavy nuclei, which will provide useful information for future experiments.
基金Supported by the Natural Science Foundation of China under Grant Nos.10775061,10875152,10875151,and 10975064the Fundamental Research Fund for Physics and Mathematic of Lanzhou University(LZULL200805)+2 种基金the Fundamental Research Funds for the Central Universities(lzujbky-2009-21)the Knowledge Innovation Project of the Chinese Academy of Sciences under Grant Nos.KJCX2-SW-N17,KJCX3-SW-N02Major State Basic Research Development Program under Grant No.2007CB815000
文摘α decay half-lives are calculated using the Qα values obtained by Semi-empirical Shell Model in the framework of the Unified Fission Model （UFM） with the Coulomb repulsion, nuclear attraction due to proximity potential, and rotational energy due to angular momentum transfer of a particle. In addition, the calculated and experimental half-lives of 425 nuclei are compared to check the validity of the model applied on α decay. The calculated half-lives of decay are in good agreement with the experimental data. Finally, some useful predications on the α decay half-lives are provided for future experiments.
基金Swedish Research Council(VR)(621-2012-3805,621-2013-4323)Gran Gustafsson Foundation
文摘In this contribution I would like to review briefly our recent studies on nuclear α formation probabilities in heavy nuclei and their indication on the underlying structure of the nuclei involved.In particular, I will show that the empirical α-formation probabilities, which can be extracted from experimental half-lives, exhibit a rather smooth function with changing proton or neutron numbers. This allows us to distinguish the role played by pairing collectivity in the clustering process. The sudden hindrance of the clustering of the nucleons around the N = 126 shell closure is due to the fact that the configuration space does not allow a proper manifestation of the pairing collectivity. The influence of the Z = 82 shell closure on the α formation properties will also be discussed. Moreover, we have evaluated the α-decay fine structure to excited 0+states in Hg and Rn isotopes as well as the α-decay from the excited 0+states in the mother nucleus. It is thus found that the α decay is sensitive to the mixture of configurations corresponding to different nuclear shapes.
基金Acknowledgements The authors are indebted to S. Heinz, J. Meng, and S. Q. Zhang for their valuable suggestions and critical reviews. This work was supported by the Major State 973 Program of China （Grant No. 2013CB834400）, the National Natural Science Foundation of China （Grant Nos. 11005004, 11175002, 11275098, and 11335002）, the Research Fund for the Doctoral Program of Higher Education （Grant No. 20110001110087）, and the China Postdoctoral Science Foundation （Grant Nos. 2012M520101 and 2013M540011）.
文摘Two recently observed ^293Lv （Z = 116） α-decay chains [Eur. Phys. J. A 48, 62 （2012）] are investigated in the framework of covariant density functional theory with PC-PK1, where the pairing correlations are treated by the Bardeen-Cooper-Schrieffer method with a density-independent zerorange force. From the calculated potential energy curves, it is found that two minima always occur, with one having an almost spherical shape and the other exhibiting a large deformed prolate shape. Originating from the ground state and the shape-isomeric state of ^293Lv, the two observed a-decay chains are constructed and the calculated Qα values are found to be in good agreement with the data.
基金the National Natural Science Foundation of China (Grant Nos. 11035001, 10975072, 10735010 and 11120101005)the National Major State Basic Research and Development of China (Grant Nos. 2010CB327803 and 2013CB834400)+4 种基金the Knowledge Innovative Program of the Chinese Academy of Sciences (Grant No. KJCX2-SW-N02)the Research Fund of Doctoral Point (RFDP) (Grant No. 20100091110028)the Project Funded by the Priority Academic Programme Development of Jiangsu Higher Education Institutions (PAPD)the Research and Innovation for College Postgraduate of JiangSu Province (Grant No. CXZZ12 0031)the Science and Technology Development Fund of Macao (Grant No.068/2011/A)
文摘The α-preformation probability is directly deduced from experimental α decay energies and half-lives in an analytical way without any modified parameters. Several other model-deduced results, are used to compare with that of the present study. The key role played by the shell effects in the v-preformation process is indicated in all these cases. In detail, the α-preformation factors of different theoretical extractions are found to have similar behavior for one given isotopic chain, implying the model-independent varying trend of the preformation probability of α particle. In addition, the formation probability of heavier particle in cluster radioactivity is also obtained, and this confirms the relationship between the cluster preformation factor and the product of the cluster and daughter proton numbers.
文摘The study of cluster structures in light nuclei is extending to the heavy nuclei in these years. As for the stable N = Z nuclei, from the lighter 8Be, 12C nuclei to the heavier 20Ne and even the 40Ca and 44Ti medium nuclei, the a cluster structures have been well studied and confirmed. In heavy nuclei, due to the dominated mean field, the existence of α cluster structure is not clear as light nuclei but some clues were found for indicating the core＋ α cluster structure in some nuclei, in particular, the 208 pb＋α structure in 212Po. We review some recent progress about the theoretical and experimental explorations of the a-clustering effects in heavy nuclei. We also discuss the possible a cluster structure of heavy nuclei from the view of a decay.
基金Supported by National Natural Science Foundation of China(11205083)Construct Program of Key Discipline in Hunan Province+3 种基金Rearch Foundation of Education Bureau of Hunan Province,China(15A159)Natural Science Foundation of Hunan Province,China(2015JJ3103,2015JJ2123)Innovation Group of Nuclear and Particle Physics in USCHunan Provincial Innovation Foundation for Postgraduate(CX2015B398)
文摘In this paper, based on the two-potential approach combining with the isospin dependent nuclear potential, we systematically compare the α preformation probabilities of odd-A nuclei between nuclear isomeric states and ground states. The results indicate that during the process of α particle preforming, the low lying nuclear isomeric states are similar to ground states. Meanwhile, in the framework of single nucleon energy level structure, we find that for nuclei with nucleon number below the magic numbers, the α preformation probabilities of high-spin states seem to be larger than low ones. For nuclei with nucleon number above the magic numbers, the α preformation probabilities of isomeric states are larger than those of ground states.
