Hypernuclei,nuclei containing one or more hyperons,serve as unique laboratories for probing the non-perturbative quantum chromodynamics(QCD).Recent progress in hypernuclear physics,driven by advanced experimental tech...Hypernuclei,nuclei containing one or more hyperons,serve as unique laboratories for probing the non-perturbative quantum chromodynamics(QCD).Recent progress in hypernuclear physics,driven by advanced experimental techniques and theoretical innovations,is briefly reviewed with a focus on key findings and unresolved challenges,such as the precise determination of the hypertriton binding energy,investigations of charge symmetry breaking in mirror hypernuclei,and the search for exotic systems,including the neutral nnΛstate.Experimental breakthroughs,including invariant-mass analyses and femtoscopy studies in heavy-ion collisions,as well as high-resolutionγ-spectroscopy,have enabled precise studies of light hypernuclei and offered critical insights into the hyperon–nucleon interaction.Theoretical progress,including ab initio calculations based on chiral effective field theory and lattice QCD,has further enhanced our understanding of hyperon–nucleon and hyperon–hyperon interactions.展开更多
The in-medium feature of nuclear force, which includes both nucleon-nucleon( NN) and hyperon-nucleon( ΛN) interactions, impacts the description of single-Λ hypernuclei. With the alternated mass number or isospin of ...The in-medium feature of nuclear force, which includes both nucleon-nucleon( NN) and hyperon-nucleon( ΛN) interactions, impacts the description of single-Λ hypernuclei. With the alternated mass number or isospin of hypernuclei, such effects may be unveiled by analyzing the systematic evolution of the bulk and single-particle properties. From a density-dependent meson-nucleon/hyperon coupling perspective, a new ΛN effective interaction in the covariant density functional(CDF) theory, namely, DD-LZ1-Λ1, is obtained by fitting the experimental data ofΛ separation energies for several single-Λ hypernuclei. It is then used to study the structure and transition properties of single-Λ hypernuclei in oxygen hyperisotopes, in comparison with those determined using several selected CDF Lagrangians. A discrepancy is explicitly observed in the isospin evolution of Λ1p spin-orbit splitting with various effective interactions, which is attributed to the divergence of the meson-hyperon coupling strengths with increasing density. In particular, the density-dependent CDFs introduce an extra contribution to reduce the value but enhance the isospin dependence of the splitting, which originates from the rearrangement terms of Λ self-energies. In addition, the characteristics of hypernuclear radii are studied along the isotopic chain. Owing to the impurity effect of theΛ hyperon, a size shrinkage is observed in the matter radii of hypernuclei compared with the cores of normal nuclei,and its magnitude is further elucidated to correlate with the incompressibility of nuclear matter. Moreover, there is a sizable model-dependent trend in which the Λ hyperon radii evolve with neutron number, which is decided partly by the in-medium NN interactions and core polarization effects.展开更多
Heavy-ion collisions are powerful tools for studying hypernuclear physics.We develop a dynamical coalescence model coupled with an ART model(version1.0) to study the production rates of light nuclear clusters and hype...Heavy-ion collisions are powerful tools for studying hypernuclear physics.We develop a dynamical coalescence model coupled with an ART model(version1.0) to study the production rates of light nuclear clusters and hypernuclei in heavy-ion reactions,for instance,the deuteron(d),triton(t),helium(~3He),and hypertriton(_A^3H)in minimum bias(0-80%centrality)~6Li+^(12)C reactions at beam energy of 3.5A GeV.The penalty factor for light clusters is extracted from the yields,and the distributions of 0 angle of particles,which provide direct suggesetions about the location of particle detectors in the near future facility-High Intensity heavy-ion Accelerator Facility(HIAF) are investigated.Our calculation demonstrates that HIAF is suitable for studying hypernuclear physics.展开更多
The isoscalar giant monopole resonances（ISGMRs）of hypernucleiAA42Ca,AA（122）Sn,andAA（210）Pb are investigated using a fully self-consistent Skyrme-Hartree-Fock plus random phase approximation method.The Skyrme-typ...The isoscalar giant monopole resonances（ISGMRs）of hypernucleiAA42Ca,AA（122）Sn,andAA（210）Pb are investigated using a fully self-consistent Skyrme-Hartree-Fock plus random phase approximation method.The Skyrme-type forces,SGII,No.5 and SAAl,are adopted to describe the nucleon-nucleon,A hyperon-nucleon and A hyperon-A hyperon（AA）interactions,respectively.For a given hyperon fraction,we find that effects of AA interaction on the properties of infinite symmetric nuclear matter and finite hypernuclei are very small.The ISGMR strengths are shifted to the high energy region when two A are added into normal nuclei.The changes are from two parts,one is due to the mean field calculations,and the other is from the residual interaction associated with A hyperons.The constrained energies are increased by about 0.5-0.7MeV,which consequently enhances the effective incompressibility modulus of hypernuclei.展开更多
A theoretical “drift-flux based thermal-hydraulic mixture-fluid coolant channel model” is presented. It is the basis to a corresponding digital “Coolant Channel Module (CCM)”. This purpose derived “Separate-Regio...A theoretical “drift-flux based thermal-hydraulic mixture-fluid coolant channel model” is presented. It is the basis to a corresponding digital “Coolant Channel Module (CCM)”. This purpose derived “Separate-Region Mixture Fluid Approach” should yield an alternative platform to the currently dominant “Separate-Phase Models” where each phase is treated separately. Contrary to it, a direct procedure could be established with the objective to simulate in an as general as possible way the steady state and transient behaviour of characteristic parameters of single- and/or (now non-separated) two-phase fluids flowing within any type of heated or non-heated coolant channels. Their validity could be confirmed by a wide range of verification and validation runs, showing very satisfactory results. The resulting universally applicable code package CCM should provide a fundamental element for the simulation of thermal-hydraulic situations over a wide range of complex systems (such as different types of heat exchangers and steam generators as being applied in both conventional but also nuclear power stations, 1D and 3D nuclear reactor cores etc). Thereby the derived set of equations for different coolant channels (distinguished by their key numbers) as appearing in these systems can be combined with other ODE-s and non-linear algebraic relations from additional parts of such an overall model. And these can then to be solved by applying an appropriate integration routine. Within the solution procedure, however, mathematical discontinuities can arise. This due to the fact that along such a coolant channel transitions from single- to two-phase flow regimes and vice versa could take place. To circumvent these difficulties it will in the presented approach be proposed that the basic coolant channel (BC) is subdivided into a number of sub-channels (SC-s), each of them being occupied exclusively by only a single or a two-phase flow regime. After an appropriate nodalization of the BC (and thus its SC-s) and after applying a “modified finite volume method” together with other special activities the fundamental set of non-linear thermal-hydraulic partial differential equations together with corresponding constitutive relations can be solved for each SC separately. As a result of such a spatial discretization for each SC type (and thus the entire BC) the wanted set of non-linear ordinary differential equations of 1st order could be established. Obviously, special attention had to be given to the varying SC entrance or outlet positions, describing the movement of boiling boundaries or mixture levels along the channel. Including even the possibility of SC-s to disappear or be created anew during a transient.展开更多
-The dynamical structure of A≤4 Λ-hypernuclei is studied by using thefew-body theoretical method.The AN interaction is taken to be the meson exchange po-tential with the single k,ω,η exchange diagrams and the box ...-The dynamical structure of A≤4 Λ-hypernuclei is studied by using thefew-body theoretical method.The AN interaction is taken to be the meson exchange po-tential with the single k,ω,η exchange diagrams and the box diagrams of π and πρ ex-change containing the intermediate state particles Σ,Δ.The Λ binding energy differenceof the mirror hypernuclei _Λ~4He and _Λ~4H is explained.It is shown that the root meansquare distances between the particles in the light hypernuclei are almost the same andthere does not exist any nuclear core.The relative motion between particles stay mainlyin 1S state.展开更多
An entirely new framework is established for developing various single- and multi-step formulations for the numerical integration of ordinary differential equations. Besides polynomials, unconventional base-functions ...An entirely new framework is established for developing various single- and multi-step formulations for the numerical integration of ordinary differential equations. Besides polynomials, unconventional base-functions with trigonometric and exponential terms satisfying different conditions are employed to generate a number of formulations. Performances of the new schemes are tested against well-known numerical integrators for selected test cases with quite satisfactory results. Convergence and stability issues of the new formulations are not addressed as the treatment of these aspects requires a separate work. The general approach introduced herein opens a wide vista for producing virtually unlimited number of formulations.展开更多
By combining the Skyrme-Hartree-Fock method with complex momentum representation(CMR),the resonant states of_(Λ)^(17)O,_(Λ)^(41)Ca,_(Λ)^(49)Ca,and_(Λ)^(57)Ni were investigated.The phase shifts for hyperon-nucleus ...By combining the Skyrme-Hartree-Fock method with complex momentum representation(CMR),the resonant states of_(Λ)^(17)O,_(Λ)^(41)Ca,_(Λ)^(49)Ca,and_(Λ)^(57)Ni were investigated.The phase shifts for hyperon-nucleus elastic scattering were determined with continuum level density(CLD),and the scattering length as well as the resonance energy were obtained by utilizing the effective range expansion.Our method,abbreviated as CMR-CLD,exhibits good consistency with traditional approaches and provides ground work for investigating scattering and resonance problems in deformed and multi-hyperon hypernuclei.展开更多
基金supported by the the National Key R&D Program of China(Grant Nos.2022YFA1604900 and 2023YFA1606703)the National Natural Science Foundation of China(Grant Nos.12025501,12435007,12405133,and 12347180)+1 种基金China Postdoctoral Science Foundation(Grant No.2023M740189)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20233381).
文摘Hypernuclei,nuclei containing one or more hyperons,serve as unique laboratories for probing the non-perturbative quantum chromodynamics(QCD).Recent progress in hypernuclear physics,driven by advanced experimental techniques and theoretical innovations,is briefly reviewed with a focus on key findings and unresolved challenges,such as the precise determination of the hypertriton binding energy,investigations of charge symmetry breaking in mirror hypernuclei,and the search for exotic systems,including the neutral nnΛstate.Experimental breakthroughs,including invariant-mass analyses and femtoscopy studies in heavy-ion collisions,as well as high-resolutionγ-spectroscopy,have enabled precise studies of light hypernuclei and offered critical insights into the hyperon–nucleon interaction.Theoretical progress,including ab initio calculations based on chiral effective field theory and lattice QCD,has further enhanced our understanding of hyperon–nucleon and hyperon–hyperon interactions.
基金the Fundamental Research Funds for the Central Universities,Lanzhou University(lzujbky-2022-sp02,lzujbky-2023-stlt01)the National Natural Science Foundation of China(11875152,12275111)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB34000000)。
文摘The in-medium feature of nuclear force, which includes both nucleon-nucleon( NN) and hyperon-nucleon( ΛN) interactions, impacts the description of single-Λ hypernuclei. With the alternated mass number or isospin of hypernuclei, such effects may be unveiled by analyzing the systematic evolution of the bulk and single-particle properties. From a density-dependent meson-nucleon/hyperon coupling perspective, a new ΛN effective interaction in the covariant density functional(CDF) theory, namely, DD-LZ1-Λ1, is obtained by fitting the experimental data ofΛ separation energies for several single-Λ hypernuclei. It is then used to study the structure and transition properties of single-Λ hypernuclei in oxygen hyperisotopes, in comparison with those determined using several selected CDF Lagrangians. A discrepancy is explicitly observed in the isospin evolution of Λ1p spin-orbit splitting with various effective interactions, which is attributed to the divergence of the meson-hyperon coupling strengths with increasing density. In particular, the density-dependent CDFs introduce an extra contribution to reduce the value but enhance the isospin dependence of the splitting, which originates from the rearrangement terms of Λ self-energies. In addition, the characteristics of hypernuclear radii are studied along the isotopic chain. Owing to the impurity effect of theΛ hyperon, a size shrinkage is observed in the matter radii of hypernuclei compared with the cores of normal nuclei,and its magnitude is further elucidated to correlate with the incompressibility of nuclear matter. Moreover, there is a sizable model-dependent trend in which the Λ hyperon radii evolve with neutron number, which is decided partly by the in-medium NN interactions and core polarization effects.
基金supported in part by the Major State Basic Research Development Program in China(Nos.2014CB845401 and2015CB856904)the National Natural Science Foundation of China(Nos.11421505,11520101004,11275250,11322547 and U1232206)Key Program of CAS for the Frontier Science(No.QYZDJ-SSW-SLH002)
文摘Heavy-ion collisions are powerful tools for studying hypernuclear physics.We develop a dynamical coalescence model coupled with an ART model(version1.0) to study the production rates of light nuclear clusters and hypernuclei in heavy-ion reactions,for instance,the deuteron(d),triton(t),helium(~3He),and hypertriton(_A^3H)in minimum bias(0-80%centrality)~6Li+^(12)C reactions at beam energy of 3.5A GeV.The penalty factor for light clusters is extracted from the yields,and the distributions of 0 angle of particles,which provide direct suggesetions about the location of particle detectors in the near future facility-High Intensity heavy-ion Accelerator Facility(HIAF) are investigated.Our calculation demonstrates that HIAF is suitable for studying hypernuclear physics.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11575060,11775014,11505058 and 11435014
文摘The isoscalar giant monopole resonances（ISGMRs）of hypernucleiAA42Ca,AA（122）Sn,andAA（210）Pb are investigated using a fully self-consistent Skyrme-Hartree-Fock plus random phase approximation method.The Skyrme-type forces,SGII,No.5 and SAAl,are adopted to describe the nucleon-nucleon,A hyperon-nucleon and A hyperon-A hyperon（AA）interactions,respectively.For a given hyperon fraction,we find that effects of AA interaction on the properties of infinite symmetric nuclear matter and finite hypernuclei are very small.The ISGMR strengths are shifted to the high energy region when two A are added into normal nuclei.The changes are from two parts,one is due to the mean field calculations,and the other is from the residual interaction associated with A hyperons.The constrained energies are increased by about 0.5-0.7MeV,which consequently enhances the effective incompressibility modulus of hypernuclei.
文摘A theoretical “drift-flux based thermal-hydraulic mixture-fluid coolant channel model” is presented. It is the basis to a corresponding digital “Coolant Channel Module (CCM)”. This purpose derived “Separate-Region Mixture Fluid Approach” should yield an alternative platform to the currently dominant “Separate-Phase Models” where each phase is treated separately. Contrary to it, a direct procedure could be established with the objective to simulate in an as general as possible way the steady state and transient behaviour of characteristic parameters of single- and/or (now non-separated) two-phase fluids flowing within any type of heated or non-heated coolant channels. Their validity could be confirmed by a wide range of verification and validation runs, showing very satisfactory results. The resulting universally applicable code package CCM should provide a fundamental element for the simulation of thermal-hydraulic situations over a wide range of complex systems (such as different types of heat exchangers and steam generators as being applied in both conventional but also nuclear power stations, 1D and 3D nuclear reactor cores etc). Thereby the derived set of equations for different coolant channels (distinguished by their key numbers) as appearing in these systems can be combined with other ODE-s and non-linear algebraic relations from additional parts of such an overall model. And these can then to be solved by applying an appropriate integration routine. Within the solution procedure, however, mathematical discontinuities can arise. This due to the fact that along such a coolant channel transitions from single- to two-phase flow regimes and vice versa could take place. To circumvent these difficulties it will in the presented approach be proposed that the basic coolant channel (BC) is subdivided into a number of sub-channels (SC-s), each of them being occupied exclusively by only a single or a two-phase flow regime. After an appropriate nodalization of the BC (and thus its SC-s) and after applying a “modified finite volume method” together with other special activities the fundamental set of non-linear thermal-hydraulic partial differential equations together with corresponding constitutive relations can be solved for each SC separately. As a result of such a spatial discretization for each SC type (and thus the entire BC) the wanted set of non-linear ordinary differential equations of 1st order could be established. Obviously, special attention had to be given to the varying SC entrance or outlet positions, describing the movement of boiling boundaries or mixture levels along the channel. Including even the possibility of SC-s to disappear or be created anew during a transient.
基金The project supported by National Natural Science Foundation of China
文摘-The dynamical structure of A≤4 Λ-hypernuclei is studied by using thefew-body theoretical method.The AN interaction is taken to be the meson exchange po-tential with the single k,ω,η exchange diagrams and the box diagrams of π and πρ ex-change containing the intermediate state particles Σ,Δ.The Λ binding energy differenceof the mirror hypernuclei _Λ~4He and _Λ~4H is explained.It is shown that the root meansquare distances between the particles in the light hypernuclei are almost the same andthere does not exist any nuclear core.The relative motion between particles stay mainlyin 1S state.
文摘An entirely new framework is established for developing various single- and multi-step formulations for the numerical integration of ordinary differential equations. Besides polynomials, unconventional base-functions with trigonometric and exponential terms satisfying different conditions are employed to generate a number of formulations. Performances of the new schemes are tested against well-known numerical integrators for selected test cases with quite satisfactory results. Convergence and stability issues of the new formulations are not addressed as the treatment of these aspects requires a separate work. The general approach introduced herein opens a wide vista for producing virtually unlimited number of formulations.
基金Supported by the National Natural Science Foundation of China(12035011,11905103,11947211,11761161001,11961141003,12022517,12375122)the National Key R&D Program of China(2023YFA1606503)+1 种基金the Science and Technology Development Fund of Macao,China(0048/2020/A1,008/2017/AFJ)the Fundamental Research Funds for the Central Universities(22120210138,22120200101)。
文摘By combining the Skyrme-Hartree-Fock method with complex momentum representation(CMR),the resonant states of_(Λ)^(17)O,_(Λ)^(41)Ca,_(Λ)^(49)Ca,and_(Λ)^(57)Ni were investigated.The phase shifts for hyperon-nucleus elastic scattering were determined with continuum level density(CLD),and the scattering length as well as the resonance energy were obtained by utilizing the effective range expansion.Our method,abbreviated as CMR-CLD,exhibits good consistency with traditional approaches and provides ground work for investigating scattering and resonance problems in deformed and multi-hyperon hypernuclei.
