A new detector array with a large solid angle coverage for the coincidence measurement of charged fragments was developed to study the breakup reaction mechanisms of weakly bound nuclear systems at energies around the...A new detector array with a large solid angle coverage for the coincidence measurement of charged fragments was developed to study the breakup reaction mechanisms of weakly bound nuclear systems at energies around the Coulomb barrier.The array has been used to explore the breakup reaction mechanisms of^(6,7)Li+^(209)Bi systems at E_(beam)=30,40,47 MeV,showing good performance in particle identification and complete kinematic measurements.Based on this,different breakup modes and breakup components were clearly distinguished,and some new breakup modes were discovered,such as^(7)Li→α+t breakup mode in6Li+209Bi system and^(7)Li→^(6)He+p breakup mode in^(7)Li+^(209)Bi system.This array can also be used to explore other breakup reaction mechanisms induced by weakly bound nuclei.展开更多
We create weakly bound Feshbach molecules in ultracold Fermi gas40K by sweeping a magnetic field across a broad Feshbach resonance point 202.2 G with a rate of 20 ms/G and perform the dissociation process using radio-...We create weakly bound Feshbach molecules in ultracold Fermi gas40K by sweeping a magnetic field across a broad Feshbach resonance point 202.2 G with a rate of 20 ms/G and perform the dissociation process using radio-frequency(RF) technology. From RF spectroscopy, we obtain the binding energy of the weakly bound molecules in the vicinity of Feshbach resonance. Our measurement also shows that the number of atoms generated from the dissociation process is different at various magnetic fields with the same RF amplitude, which gives us a deeper understanding of weakly bound Feshbach molecules.展开更多
The present work provides a literature survey of breakup reactions induced by weakly bound nuclei at energies around the Coulomb barrier.We review the inclusive and exclusive breakup data of stable weakly bound nuclei...The present work provides a literature survey of breakup reactions induced by weakly bound nuclei at energies around the Coulomb barrier.We review the inclusive and exclusive breakup data of stable weakly bound nuclei^(6.7)Li and^(9)Be,as well as light radioactive projectiles reported within the last decade.Several theoretical and data analysis tools used to describe the data are reviewed as well.Similarities and differences in the behavior of breakup reactions involving these weakly bound nuclei are discussed.It is found that,for^(6.7)Li and^(9)Be,transfer-triggered breakup is a significant mode,which,however,is not observed in drip-line nuclear systems.Moreover,differences in the breakup dynamics and the contribution of breakup to the total reaction cross section at energies close to the Coulomb barrier seem to emerge between neutron-halo and proton-halo systems.Possible explanations for the observed differences are discussed.展开更多
The^(6)Li+^(89)Y experiment was performed to explore the reaction mechanism induced by a weakly bound nucleus^(6)Li and its cluster configuration.The particle-γcoincidence method was used to identify the different re...The^(6)Li+^(89)Y experiment was performed to explore the reaction mechanism induced by a weakly bound nucleus^(6)Li and its cluster configuration.The particle-γcoincidence method was used to identify the different reaction channels.Theγ-rays coincident with^(3)He/^(3)H indicate that the^(3)H/^(3)He stripping reaction plays a significant role in the formation of Zr/Nb isotopes.The obtained results support the existence of a^(3)He-^(3)H cluster in^(6)Li.Direct and sequential transfer reactions are adequately discussed,and the FRESCO code is used to perform precise finite-range cyclic redundancy check calculations.In the microscopic calculation,direct cluster transfer is more predominant than sequential transfer in^(3)H transfer.However,the direct cluster transfer is of comparable magnitude to the sequential transfer in the^(3)He transfer.展开更多
A machine learning approach based on Bayesian neural networks was developed to predict the complete fusion cross-sections of weakly bound nuclei.This method was trained and validated using 475 experimental data points...A machine learning approach based on Bayesian neural networks was developed to predict the complete fusion cross-sections of weakly bound nuclei.This method was trained and validated using 475 experimental data points from 39 reaction systems induced by ^(6,7)Li,^(9)Be,and ^(10)B.The constructed Bayesian neural network demonstrated a high degree of accuracy in evaluating complete fusion cross-sections.By comparing the predicted cross-sections with those obtained from a single-barrier penetration model,the suppression effect of ^(6,7)Li and ^(9)Be with a stable nucleus was systematically analyzed.In the cases of ^(6)Li and ^(7)Li,less suppression was predicted for relatively light-mass targets than for heavy-mass targets,and a notably distinct dependence relationship was identified,suggesting that the predominant breakup mechanisms might change in different mass target regions.In addition,minimum suppression factors were predicted to occur near target nuclei with neutron-closed shell.展开更多
We have studied the effects of the finite range on the fusion and/or breakup of ^6He^＋238U and ^11Li＋^208pb Pb dynamic polarization potential approach. It has been found of the interaction between the fragments of t...We have studied the effects of the finite range on the fusion and/or breakup of ^6He^＋238U and ^11Li＋^208pb Pb dynamic polarization potential approach. It has been found of the interaction between the fragments of the projectile systems at near barrier energies within the framework of that at near barrier energies the maximum flux is lost to the breakup channel and at energies well above the Coulomb barrier the fusion coupled with the breakup channel opens up, initially with sharp rise and later becoming saturated at energy nearly twice of the Coulomb barrier. Further, it is found that the breakup cross section increases with the increasing range of the interaction between the fragments of the projectile while the fusion coupled with the breakup channel cross section decreases with the increasing range.展开更多
One-neutron stripping process between^(6)Li and^(209)Bi was studied at 28,30,and 34 MeV using the in-beamγ-ray spectroscopy method.Theγ-γcoincident analysis clearly identified twoγ-rays feeding the ground and long...One-neutron stripping process between^(6)Li and^(209)Bi was studied at 28,30,and 34 MeV using the in-beamγ-ray spectroscopy method.Theγ-γcoincident analysis clearly identified twoγ-rays feeding the ground and long-lived isomeric states,which were employed to determine the cross section.The one-neutron stripping cross sections were similar to the cross sections of complete fusion in the^(6)Li+^(209)Bi system,but the one-neutron stripping cross sections decreased more gradually at the sub-barrier region.A coupled-reaction-channel calculation was performed to study the detailed reaction mechanism of the one-neutron stripping process in^(6)Li.The calculations indicated that the first excited state of 5 Li is critical in the actual one-neutron transfer mechanism,and the valence proton of 209Bi can be excited to the low-lying excited state in(^(6)Li,^(5)Li)reaction,unlike in the(d,p)reaction.展开更多
We report full-dimensional and fully coupled quantum bound-state calculations of the J=1 intra-and intermolecular rovibrational states of two isotopologues of the hydrogen chloride-water dimer,HClH_(2)O(HH)and DCl-H_(...We report full-dimensional and fully coupled quantum bound-state calculations of the J=1 intra-and intermolecular rovibrational states of two isotopologues of the hydrogen chloride-water dimer,HClH_(2)O(HH)and DCl-H_(2)O(DH).The present study complements our recent theoretical investigations of the J=0 nine-dimensional(9D)vibrational level structure of these and two other H/D isotopologues of this noncovalently bound molecular complex,and employs the same accurate 9D permutation invariant polynomial-neural network potential energy surface.The calculations yield all intramolecular vibrational fundamentals of the HH and DH dimers and the low-energy intermolecular rovibrational states in these intramolecular vibrational manifolds.The results are compared with those of the 9D J=0 calculations of the same dimers.The energy differences between the K=1 and K=0 eigenstates exhibit pronounced variations with the intermolecular rovibrational states,for which a qualitative explanation is provided.展开更多
The coordinate-space Hartree-Fock-Bogoliubov（HFB） approach with quasiparticle blocking has been applied to study the odd-A weakly bound nuclei ^17,19B and ^37Mg,in which halo structures have been reported in experim...The coordinate-space Hartree-Fock-Bogoliubov（HFB） approach with quasiparticle blocking has been applied to study the odd-A weakly bound nuclei ^17,19B and ^37Mg,in which halo structures have been reported in experiments.The Skyrme nuclear forces SLy4 and UNEDF1 have been adopted in our calculations.The results with and without blocking have been compared to demonstrate the emergence of deformed halo structures due to blocking effects.In our calculations,^19B and ^37Mg have remarkable features of deformed halos.展开更多
By using the ground and high-altitude observation data,NCEP 6 h reanalysis data and CINRAD/SA radar observation data,the circulation situation,the atmospheric stability degree and the radar echo characteristics of a s...By using the ground and high-altitude observation data,NCEP 6 h reanalysis data and CINRAD/SA radar observation data,the circulation situation,the atmospheric stability degree and the radar echo characteristics of a strong convection weather which occurred in Nantong area of Jiangsu Province on June 14 in 2009 were analyzed.The results showed that the hailstone happened in the large scale background of coastal trough rear which was established by the northeast low vortex.The warm air in the middle-low layer was covered with the cold air in 500 hPa,which provided the favorable condition for the occurrence of strong convection weather which included the hailstone,the thunderstorm,the strong wind and so on.Seen from the analysis on the radar echo,the windstorm which induced this strong convective weather had the characteristics of super monomer windstorm.In the northwest and the southeast,there were 2 obvious outflow boundaries and the overhanging structure characteristics.The strong vertical shear and the suitable frozen layer height in the middle-low layer of troposphere were also favorable to fall the hailstone.展开更多
We consider a generalization of Baum-Katz theorem for random variables satisfying some cover conditions.Consequently,we get the results for many dependent structures,such as END,ϱ^(*)mixing,ϱ^(-)mixing andφ-mixing,etc.
We obtain the operator norms of the n-dimensional fractional Hardy operator Hα（0 〈 α 〈 n） from weighted Lebesgue spaces Lp｜x｜p（R^n） to weighted weak Lebesgue spacesLq,∞｜x｜β（R^n）.
The coupled reaction channel approach has proven to be quite effective in explaining the mechanism of nucleon transfer in heavy-ion reactions.Nevertheless,significant ambiguities remain regarding the selection of pote...The coupled reaction channel approach has proven to be quite effective in explaining the mechanism of nucleon transfer in heavy-ion reactions.Nevertheless,significant ambiguities remain regarding the selection of potential parameters and the states of the nuclei that should be coupled together for a specific reaction channel.In this study,the excitation functions for one-and two-neutron transfer in^(6.7)Li-induced reactions on various targets were analyzed using the coupled reaction channel formalism.Spectroscopic amplitudes were taken from the existing literature and shell model calculations.The one-neutron transfer cross sections from^(6)Li+^(93)Nb and^(7)Li+^(115)In reactions were reasonably well reproduced by coupled reaction channel calculations.A reasonable match for the measured cross sections was also obtained for the two-neutron transfer in the^(7)Li+^(181)Ta reaction by employing the extreme cluster model.展开更多
Coincidence measurements of breakup fragments in reactions of^(6.7)with^(209)Bi at energies around and above the Coulomb barrier were carried out using a large solid-angle covered detector array.Through the Q values a...Coincidence measurements of breakup fragments in reactions of^(6.7)with^(209)Bi at energies around and above the Coulomb barrier were carried out using a large solid-angle covered detector array.Through the Q values along with the relative energies of the breakup fragments,different breakup components(prompt breakups and delayed breakups)and different breakup modes(α+t,α+d,α+p,andα+α)are distinguished.A new breakup mode,α+t,is observed in^(6)Li-induced reactions at energies above the Coulomb barrier.Correlations between breakup modes and breakup components as well as their variations with the incident energy are investigated.The results will help us better understand the breakup effects of weakly bound nuclei on the suppression of a complete fusion,particularly for the above-barrier energies.展开更多
This article analyzes the fusion dynamics of loosely bound and stable projectiles with Zr-target isotopes within the context of the coupled channel approach and the energy-dependent Woods-Saxon potential model （EDWSP...This article analyzes the fusion dynamics of loosely bound and stable projectiles with Zr-target isotopes within the context of the coupled channel approach and the energy-dependent Woods-Saxon potential model （EDWSP model）. In the case of the 2SSi＋90Zr reaction, the coupling to the inelastic surface excitations results in an adequate description of the observed fusion dynamics while in case of the 2Ssi ＋ 94Zr reaction, the coupling to collective surface vibrational states as well as the neutron （multi-neutron） transfer channel is necessary in the coupled channel calculations to reproduce the below-barrier fusion data. However, the EDWSP model calculation provides an accurate explanation of the fusion data of 2Ssi＋ 90,94Zr reactions in the domain of the Coulomb barrier. In the fusion of the 6Li＋90Zr reaction, the inclusion of the nuclear structure degrees of freedom recovers the observed sub-barrier fusion enhancement but results in suppression of the above barrier fusion data by 34% with respect to the coupled channel calculations. Using EDWSP model calculations, this suppression factor is reduced by 14% and consequently, the above-barrier fusion data of 6Li＋90Zr reaction is suppressed by 20% with reference to the EDWSP model calculations. Such fusion suppression at above-barrier energies can be correlated with the breakupof the projectile （6Li） before reaching the fusion barrier, as a consequence of low binding energy.展开更多
Continuum Discretized Coupled-Channel（CDCC） model calculations of total, complete and incomplete fusion cross sections for reactions of the weakly bound 6Li with 144,154Sm targets at energies around the Coulomb barr...Continuum Discretized Coupled-Channel（CDCC） model calculations of total, complete and incomplete fusion cross sections for reactions of the weakly bound 6Li with 144,154Sm targets at energies around the Coulomb barrier are presented. In the cluster structure frame of 6Li→α＋d, short-range absorption potentials are considered for the interactions between the ground state of the projectile 6Li and α-d fragments with the target. In order to separately calculate complete and incomplete fusion and to reduce double-counting, the corresponding absorption potentials are chosen to be of different range. Couplings to low-lying excited states 2＋, 3-of 144Sm and 2＋, 4＋ of 154Sm are included. So, the effect on total fusion from the excited states of the target is investigated. Similarly, the effect on fusion due to couplings to resonance breakup states of 6Li, namely, l = 2,Jπ= 3＋, 2＋, 1＋ is also calculated.The latter effect is determined by using two approaches,（a） by considering only resonance state couplings and（b）by omitting these states from the full discretized energy space. Among other things, it is found that both resonance and non-resonance continuum breakup couplings produce fusion suppression at all the energies considered.展开更多
The reduced strong absorption distance d_(S) and Coulomb barrier height V_(B) are extracted from the quarter-point recipe from a series of experimental elastic scattering angle distributions.The nuclei with different ...The reduced strong absorption distance d_(S) and Coulomb barrier height V_(B) are extracted from the quarter-point recipe from a series of experimental elastic scattering angle distributions.The nuclei with different binding energies are systematically studied as the projectile,including the tightly bound,weakly bound,and halo nuclei.It is found that the mean d_(S) for halo nuclei is significantly larger than that of tightly and weakly bound nuclei.The complex behavior of d_(S) regarding the binding energy and properties of the target is observed for halo nuclei.The linear relationship of the reduced distance with system size may be used to estimate the Coulomb barrier radius R_(B),which is difficult to obtain from fusion reactions.The rule of V_(B) concerning the Coulomb parameter z is in agreement with other theoretical barrier laws extracted from the fusion reaction.Furthermore,the reason why the binding energy or deformation has little effect on the linear relationship of V_(B) as a function of z is clarified.展开更多
The complete and incomplete fusion cross sections for ^(6)Li+^(209)Bi were measured using the in-beamγ-ray method around the Coulomb barrier.The cross sections of(deuteron captured)incomplete fusion(ICF)products were...The complete and incomplete fusion cross sections for ^(6)Li+^(209)Bi were measured using the in-beamγ-ray method around the Coulomb barrier.The cross sections of(deuteron captured)incomplete fusion(ICF)products were re-quantified experimentally for this reaction system.The results reveal that the ICF cross section is equivalent to that of complete fusion(CF)above the Coulomb barrier and dominant near or below the Coulomb barrier.A theoretical calculation based on the continuum discretized coupled channel(CDCC)method was performed for the aforementioned CF and ICF cross sections;the result is consistent with the experiments.The universal fusion function(UFF)was also compared with the measured CF cross section for different barrier parameters,demonstrating that the CF suppression factor is significantly influenced by the choice of potential,which can reflect both dynamic and static effects of breakup on the fusion process.展开更多
The complete and incomplete fusion cross section as well as one-neutron stripping process of ^(6)Li+^(94)Zr system were measured at the energies around the Coulomb barrier by onlineγ-ray method.In addition to a 30%su...The complete and incomplete fusion cross section as well as one-neutron stripping process of ^(6)Li+^(94)Zr system were measured at the energies around the Coulomb barrier by onlineγ-ray method.In addition to a 30%suppression factor when compared with the measured total fusion process,the complete fusion cross section in ^(6)Li+^(94)Zr system was observed to be significantly lower than those in the nearby ^(6)Li+^(90,96)Zr system.The new experimental result implies that the coupling with breakup channel in the ^(6)Li-induced fusion processes can be affected by the inner structure of the target,which is still not clear in any available model calculation.For the one-neutron stripping process,the direct production cross sections for each level in 95Zr were extracted and compared with the coupled reaction channel calculation,offering a unique opportunity to examine the single-particle nature of the produced excited states.Given the fact that an overall overestimation of the production cross section for 954-keV and1618-keV levels was observed in the comparison,further investigation is highly demanded in order to understand the full reaction mechanism for the one-neutron stripping process induced by ^(6)Li.展开更多
基金supported by the National Key R&D Program of China(Nos.2022YFA1602302 and 2023YFA1606402)the National Natural Science Foundation of China(Nos.U2167204,12175314,12235020 and 12275360)+2 种基金the Continuous-Support Basic Scientific Research Projectthe"111 Center"the China Scholarship Council(CSC)。
文摘A new detector array with a large solid angle coverage for the coincidence measurement of charged fragments was developed to study the breakup reaction mechanisms of weakly bound nuclear systems at energies around the Coulomb barrier.The array has been used to explore the breakup reaction mechanisms of^(6,7)Li+^(209)Bi systems at E_(beam)=30,40,47 MeV,showing good performance in particle identification and complete kinematic measurements.Based on this,different breakup modes and breakup components were clearly distinguished,and some new breakup modes were discovered,such as^(7)Li→α+t breakup mode in6Li+209Bi system and^(7)Li→^(6)He+p breakup mode in^(7)Li+^(209)Bi system.This array can also be used to explore other breakup reaction mechanisms induced by weakly bound nuclei.
基金Project supported by the National Basic Research Program of China （Grant No. 2011CB921601）, the National Natural Science Foundation of China （Grant No. 11234008）, the Project for Excellent Research Team of China （Grant No. 61121064）, and the Doctoral Program Foundation of Ministry of Education, China （Grant No. 20111401130001）.
文摘We create weakly bound Feshbach molecules in ultracold Fermi gas40K by sweeping a magnetic field across a broad Feshbach resonance point 202.2 G with a rate of 20 ms/G and perform the dissociation process using radio-frequency(RF) technology. From RF spectroscopy, we obtain the binding energy of the weakly bound molecules in the vicinity of Feshbach resonance. Our measurement also shows that the number of atoms generated from the dissociation process is different at various magnetic fields with the same RF amplitude, which gives us a deeper understanding of weakly bound Feshbach molecules.
基金supported by the National Key R&D Program of China(2022YFA1602302)the National Natural Science Foundation of China(U2167204,12175314 and 12235020)+1 种基金the Leading Innovation Project(LC202309000201)the Director’s Foundation of Department of Nuclear Physics,China Institute of Atomic Energy(12SZJJ-202305).
文摘The present work provides a literature survey of breakup reactions induced by weakly bound nuclei at energies around the Coulomb barrier.We review the inclusive and exclusive breakup data of stable weakly bound nuclei^(6.7)Li and^(9)Be,as well as light radioactive projectiles reported within the last decade.Several theoretical and data analysis tools used to describe the data are reviewed as well.Similarities and differences in the behavior of breakup reactions involving these weakly bound nuclei are discussed.It is found that,for^(6.7)Li and^(9)Be,transfer-triggered breakup is a significant mode,which,however,is not observed in drip-line nuclear systems.Moreover,differences in the breakup dynamics and the contribution of breakup to the total reaction cross section at energies close to the Coulomb barrier seem to emerge between neutron-halo and proton-halo systems.Possible explanations for the observed differences are discussed.
基金supported by the National Natural Science Foundation of China under Grant Nos.U2167204,11975040,111 Center(B20065)Brazilian authors were supported in part by local funding agencies CNPq+10 种基金FAPERJCAPESand INCT-FNA(Instituto Nacional de Ciência e Tecnologia,Física Nuclear e Aplicacoes)Research Project No.464898/2014-5Marco Siciliano's work was partially supported by the US Department of EnergyOffice of Scienceand Office of Nuclear Physics(DE-AC02-06CH11357)supported by Nuclear Energy Development and Research Project No.HNKF202224(28)Ling Chuang Research Project of the China National Nuclear Corporation No.CNNCLCKY-2023 and No.20221024000072F6-0002-7Guangdong Key Research and Development Program No.2020B040420005Guangdong Basic and Applied Basic Research Foundation No.2021B1515120027。
文摘The^(6)Li+^(89)Y experiment was performed to explore the reaction mechanism induced by a weakly bound nucleus^(6)Li and its cluster configuration.The particle-γcoincidence method was used to identify the different reaction channels.Theγ-rays coincident with^(3)He/^(3)H indicate that the^(3)H/^(3)He stripping reaction plays a significant role in the formation of Zr/Nb isotopes.The obtained results support the existence of a^(3)He-^(3)H cluster in^(6)Li.Direct and sequential transfer reactions are adequately discussed,and the FRESCO code is used to perform precise finite-range cyclic redundancy check calculations.In the microscopic calculation,direct cluster transfer is more predominant than sequential transfer in^(3)H transfer.However,the direct cluster transfer is of comparable magnitude to the sequential transfer in the^(3)He transfer.
基金supported by National Natural Science Foundation of China(Nos.12105080 and 12375123)China Postdoctoral Science Foundation(No.2023M731015)Natural Science Foundation of Henan Province(No.242300422048).
文摘A machine learning approach based on Bayesian neural networks was developed to predict the complete fusion cross-sections of weakly bound nuclei.This method was trained and validated using 475 experimental data points from 39 reaction systems induced by ^(6,7)Li,^(9)Be,and ^(10)B.The constructed Bayesian neural network demonstrated a high degree of accuracy in evaluating complete fusion cross-sections.By comparing the predicted cross-sections with those obtained from a single-barrier penetration model,the suppression effect of ^(6,7)Li and ^(9)Be with a stable nucleus was systematically analyzed.In the cases of ^(6)Li and ^(7)Li,less suppression was predicted for relatively light-mass targets than for heavy-mass targets,and a notably distinct dependence relationship was identified,suggesting that the predominant breakup mechanisms might change in different mass target regions.In addition,minimum suppression factors were predicted to occur near target nuclei with neutron-closed shell.
文摘We have studied the effects of the finite range on the fusion and/or breakup of ^6He^＋238U and ^11Li＋^208pb Pb dynamic polarization potential approach. It has been found of the interaction between the fragments of the projectile systems at near barrier energies within the framework of that at near barrier energies the maximum flux is lost to the breakup channel and at energies well above the Coulomb barrier the fusion coupled with the breakup channel opens up, initially with sharp rise and later becoming saturated at energy nearly twice of the Coulomb barrier. Further, it is found that the breakup cross section increases with the increasing range of the interaction between the fragments of the projectile while the fusion coupled with the breakup channel cross section decreases with the increasing range.
基金the National Nature Science Foundation of China(Nos.U2167204,11975040,and U1832130)the Brazilian funding agencies CAPES,CNPq,FAPERJ,and the INCT-FNA(Instituto Nacional de Ciência e Tecnologia-Física Nuclear e Aplicações)+5 种基金research project 464898/2014-5.S.P.Hu was supported by Guang dong Key Research And Development Program(No.2020B040420005)Guang dong Basic and Applied Basic Research Foundation(No.2021B1515120027)Ling Chuang Research Project of China National Nuclear Corporation(No.20221024000072F6-0002-7)Nuclear Energy Development and Research Project(No.HNKF202224(28))the‘111’center(B20065)the U.S.Department of Energy,Office of Science,Office of Nuclear Physics,under contract number DE-AC02-06CH1135.
文摘One-neutron stripping process between^(6)Li and^(209)Bi was studied at 28,30,and 34 MeV using the in-beamγ-ray spectroscopy method.Theγ-γcoincident analysis clearly identified twoγ-rays feeding the ground and long-lived isomeric states,which were employed to determine the cross section.The one-neutron stripping cross sections were similar to the cross sections of complete fusion in the^(6)Li+^(209)Bi system,but the one-neutron stripping cross sections decreased more gradually at the sub-barrier region.A coupled-reaction-channel calculation was performed to study the detailed reaction mechanism of the one-neutron stripping process in^(6)Li.The calculations indicated that the first excited state of 5 Li is critical in the actual one-neutron transfer mechanism,and the valence proton of 209Bi can be excited to the low-lying excited state in(^(6)Li,^(5)Li)reaction,unlike in the(d,p)reaction.
基金the National Science Foundation for its partial support of this research through the Grants CHE-2054616 and CHE-2054604,respectively。
文摘We report full-dimensional and fully coupled quantum bound-state calculations of the J=1 intra-and intermolecular rovibrational states of two isotopologues of the hydrogen chloride-water dimer,HClH_(2)O(HH)and DCl-H_(2)O(DH).The present study complements our recent theoretical investigations of the J=0 nine-dimensional(9D)vibrational level structure of these and two other H/D isotopologues of this noncovalently bound molecular complex,and employs the same accurate 9D permutation invariant polynomial-neural network potential energy surface.The calculations yield all intramolecular vibrational fundamentals of the HH and DH dimers and the low-energy intermolecular rovibrational states in these intramolecular vibrational manifolds.The results are compared with those of the 9D J=0 calculations of the same dimers.The energy differences between the K=1 and K=0 eigenstates exhibit pronounced variations with the intermolecular rovibrational states,for which a qualitative explanation is provided.
基金Supported by National Key Basic Research Program of China(2013CB83440)National Natural Science Foundation of China(11375016,11235001,11320101004)Research Fund for Doctoral Program of Higher Education of China(20130001110001)
文摘The coordinate-space Hartree-Fock-Bogoliubov（HFB） approach with quasiparticle blocking has been applied to study the odd-A weakly bound nuclei ^17,19B and ^37Mg,in which halo structures have been reported in experiments.The Skyrme nuclear forces SLy4 and UNEDF1 have been adopted in our calculations.The results with and without blocking have been compared to demonstrate the emergence of deformed halo structures due to blocking effects.In our calculations,^19B and ^37Mg have remarkable features of deformed halos.
基金Supported by Jiangsu Province Important Science Technology Support and Independent Innovation Demonstration Project (BE2008618)
文摘By using the ground and high-altitude observation data,NCEP 6 h reanalysis data and CINRAD/SA radar observation data,the circulation situation,the atmospheric stability degree and the radar echo characteristics of a strong convection weather which occurred in Nantong area of Jiangsu Province on June 14 in 2009 were analyzed.The results showed that the hailstone happened in the large scale background of coastal trough rear which was established by the northeast low vortex.The warm air in the middle-low layer was covered with the cold air in 500 hPa,which provided the favorable condition for the occurrence of strong convection weather which included the hailstone,the thunderstorm,the strong wind and so on.Seen from the analysis on the radar echo,the windstorm which induced this strong convective weather had the characteristics of super monomer windstorm.In the northwest and the southeast,there were 2 obvious outflow boundaries and the overhanging structure characteristics.The strong vertical shear and the suitable frozen layer height in the middle-low layer of troposphere were also favorable to fall the hailstone.
基金Supported by the National Natural Science Foundation of China(11701403).
文摘We consider a generalization of Baum-Katz theorem for random variables satisfying some cover conditions.Consequently,we get the results for many dependent structures,such as END,ϱ^(*)mixing,ϱ^(-)mixing andφ-mixing,etc.
基金Himanshu Sharma acknowledges the MHRD Research Fellowship,and Rishabh Kumar acknowledges the DST INSPIRE(IF180078)Research Fellowship from theGovernmentof India。
文摘The coupled reaction channel approach has proven to be quite effective in explaining the mechanism of nucleon transfer in heavy-ion reactions.Nevertheless,significant ambiguities remain regarding the selection of potential parameters and the states of the nuclei that should be coupled together for a specific reaction channel.In this study,the excitation functions for one-and two-neutron transfer in^(6.7)Li-induced reactions on various targets were analyzed using the coupled reaction channel formalism.Spectroscopic amplitudes were taken from the existing literature and shell model calculations.The one-neutron transfer cross sections from^(6)Li+^(93)Nb and^(7)Li+^(115)In reactions were reasonably well reproduced by coupled reaction channel calculations.A reasonable match for the measured cross sections was also obtained for the two-neutron transfer in the^(7)Li+^(181)Ta reaction by employing the extreme cluster model.
基金National Natural Science Foundation of China(11635015,U1832130,11975040)State Key Laboratory of Software Development Environment(SKLSDE-2020ZX-16)+1 种基金the Continuous Basic Scientific Research Project(WDJC-2019-13)the Leading Innovation Project(LC192209000701,LC202309000201)。
文摘Coincidence measurements of breakup fragments in reactions of^(6.7)with^(209)Bi at energies around and above the Coulomb barrier were carried out using a large solid-angle covered detector array.Through the Q values along with the relative energies of the breakup fragments,different breakup components(prompt breakups and delayed breakups)and different breakup modes(α+t,α+d,α+p,andα+α)are distinguished.A new breakup mode,α+t,is observed in^(6)Li-induced reactions at energies above the Coulomb barrier.Correlations between breakup modes and breakup components as well as their variations with the incident energy are investigated.The results will help us better understand the breakup effects of weakly bound nuclei on the suppression of a complete fusion,particularly for the above-barrier energies.
基金Supported by Dr.D.S.Kothari Post-Doctoral Fellowship Scheme sponsored by University Grants Commission(UGC),New Delhi,India
文摘This article analyzes the fusion dynamics of loosely bound and stable projectiles with Zr-target isotopes within the context of the coupled channel approach and the energy-dependent Woods-Saxon potential model （EDWSP model）. In the case of the 2SSi＋90Zr reaction, the coupling to the inelastic surface excitations results in an adequate description of the observed fusion dynamics while in case of the 2Ssi ＋ 94Zr reaction, the coupling to collective surface vibrational states as well as the neutron （multi-neutron） transfer channel is necessary in the coupled channel calculations to reproduce the below-barrier fusion data. However, the EDWSP model calculation provides an accurate explanation of the fusion data of 2Ssi＋ 90,94Zr reactions in the domain of the Coulomb barrier. In the fusion of the 6Li＋90Zr reaction, the inclusion of the nuclear structure degrees of freedom recovers the observed sub-barrier fusion enhancement but results in suppression of the above barrier fusion data by 34% with respect to the coupled channel calculations. Using EDWSP model calculations, this suppression factor is reduced by 14% and consequently, the above-barrier fusion data of 6Li＋90Zr reaction is suppressed by 20% with reference to the EDWSP model calculations. Such fusion suppression at above-barrier energies can be correlated with the breakupof the projectile （6Li） before reaching the fusion barrier, as a consequence of low binding energy.
基金partly supported by the NSF of China(11120101005,11275248,11525524,11621131001,11647601,11711540016)973 Program of China(2013CB834400)the Key Research Program of Frontier Sciences of CAS.H.Q.Z.from NSF China(11375266)
文摘Continuum Discretized Coupled-Channel（CDCC） model calculations of total, complete and incomplete fusion cross sections for reactions of the weakly bound 6Li with 144,154Sm targets at energies around the Coulomb barrier are presented. In the cluster structure frame of 6Li→α＋d, short-range absorption potentials are considered for the interactions between the ground state of the projectile 6Li and α-d fragments with the target. In order to separately calculate complete and incomplete fusion and to reduce double-counting, the corresponding absorption potentials are chosen to be of different range. Couplings to low-lying excited states 2＋, 3-of 144Sm and 2＋, 4＋ of 154Sm are included. So, the effect on total fusion from the excited states of the target is investigated. Similarly, the effect on fusion due to couplings to resonance breakup states of 6Li, namely, l = 2,Jπ= 3＋, 2＋, 1＋ is also calculated.The latter effect is determined by using two approaches,（a） by considering only resonance state couplings and（b）by omitting these states from the full discretized energy space. Among other things, it is found that both resonance and non-resonance continuum breakup couplings produce fusion suppression at all the energies considered.
基金This study is supported by the National Key R&D Program of China(2022YFA1602302)the National Natural Science Foundation of China(12235020,12275360,12175314,12175313,U2167204)+3 种基金the Continuous Basic Scientific Research Project(WDJC-2019-13)the Leading Innovation Project(LC192209000701,LC202309000201)the project supported by the Director's Foundation of Department of Nuclear Physics,China Institute of Atomic Energy(12SZJJ-202305)the Young Talent Development Foundation(YC212212000101)。
文摘The reduced strong absorption distance d_(S) and Coulomb barrier height V_(B) are extracted from the quarter-point recipe from a series of experimental elastic scattering angle distributions.The nuclei with different binding energies are systematically studied as the projectile,including the tightly bound,weakly bound,and halo nuclei.It is found that the mean d_(S) for halo nuclei is significantly larger than that of tightly and weakly bound nuclei.The complex behavior of d_(S) regarding the binding energy and properties of the target is observed for halo nuclei.The linear relationship of the reduced distance with system size may be used to estimate the Coulomb barrier radius R_(B),which is difficult to obtain from fusion reactions.The rule of V_(B) concerning the Coulomb parameter z is in agreement with other theoretical barrier laws extracted from the fusion reaction.Furthermore,the reason why the binding energy or deformation has little effect on the linear relationship of V_(B) as a function of z is clarified.
基金Supported by the National Nature Science Foundation of China(U2167204,11975040,1832130)The Brazilian authors thank the partial financial support from CNPq,FAPERJ,and INCT-FNA(Instituto Nacional de Ciência e Tecnologia,Física Nuclear e Aplicações),research Project No.(464898/2014-5)+4 种基金supported by(M.S.)the U.S.Department of Energy,Office of Science,and Office of Nuclear Physics(DE-AC02-06CH11357)supported By the Key Research and Development Program of Guangdong Province,China(2020B040420005)the Basic and Applied Basic Research Foundation of Guangdong Province,China(2021B1515120027)LingChuang Research Project of China National Nuclear Corporation(20221024000072F6-0002-7)the Nuclear Energy Development and Research Project(HNKF202224(28)),and the'111'Center(B20065).
文摘The complete and incomplete fusion cross sections for ^(6)Li+^(209)Bi were measured using the in-beamγ-ray method around the Coulomb barrier.The cross sections of(deuteron captured)incomplete fusion(ICF)products were re-quantified experimentally for this reaction system.The results reveal that the ICF cross section is equivalent to that of complete fusion(CF)above the Coulomb barrier and dominant near or below the Coulomb barrier.A theoretical calculation based on the continuum discretized coupled channel(CDCC)method was performed for the aforementioned CF and ICF cross sections;the result is consistent with the experiments.The universal fusion function(UFF)was also compared with the measured CF cross section for different barrier parameters,demonstrating that the CF suppression factor is significantly influenced by the choice of potential,which can reflect both dynamic and static effects of breakup on the fusion process.
基金supported by the National Nature Science Foundation of China(U2167204,11975040,1832130,12375130)the Director's Foundation of Department of Nuclear Physics,China Institute of Atomic Energy 12SZJJ-202305+4 种基金the partial support from financial agencies FAPERJ,CNPq,and INTC-FNA(Instituto Nacional de Ciência e Tecnologia-Física Nuclear e Aplica??es),research Project(464898/2014-5)supported by Guang dong Key Research And Development Program(2020B040420005)Guang dong Basic and Applied Basic Research Foundation(2021B1515120027)Ling Chuang Research Project of China National Nuclear Corporation(20221024000072F6-0002-7)Nuclear Energy Development and Research Project(HNKF202224(28))。
文摘The complete and incomplete fusion cross section as well as one-neutron stripping process of ^(6)Li+^(94)Zr system were measured at the energies around the Coulomb barrier by onlineγ-ray method.In addition to a 30%suppression factor when compared with the measured total fusion process,the complete fusion cross section in ^(6)Li+^(94)Zr system was observed to be significantly lower than those in the nearby ^(6)Li+^(90,96)Zr system.The new experimental result implies that the coupling with breakup channel in the ^(6)Li-induced fusion processes can be affected by the inner structure of the target,which is still not clear in any available model calculation.For the one-neutron stripping process,the direct production cross sections for each level in 95Zr were extracted and compared with the coupled reaction channel calculation,offering a unique opportunity to examine the single-particle nature of the produced excited states.Given the fact that an overall overestimation of the production cross section for 954-keV and1618-keV levels was observed in the comparison,further investigation is highly demanded in order to understand the full reaction mechanism for the one-neutron stripping process induced by ^(6)Li.
