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 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
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
-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
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
Based on the beyond-mean-field Skyrme-Hartree-Fock model,impurity effects of theΛhyperon in the hypernuclear systems^(25)ΛMg and^(29)ΛSi are investigated,respectively.Four cases,in which theΛhyperon occupies the s...Based on the beyond-mean-field Skyrme-Hartree-Fock model,impurity effects of theΛhyperon in the hypernuclear systems^(25)ΛMg and^(29)ΛSi are investigated,respectively.Four cases,in which theΛhyperon occupies the single-particle orbitals L[000]1+/2,L[110]1-/2,L[101]3-/2 and L[101]1-/2,are focused.In each case,the potential energy surface and the energy curves projected on certain angular momenta are employed to show the influence of theΛhyperon on the nuclear core.Beside the shrinkage effect that is induced by theΛhyperon occupying the sΛorbital,it is found that theΛhyperon on the pΛorbital,L[110]1-/2,drives the nuclear core toward a prolate shape,while the ones on the other two pΛorbitals,L[101]3-/2 and L[101]1-/2,drive the nuclear core toward an oblate shape.The energy spectra and the corresponding intra-band E2 transition rates for the rotational bands are given as a prediction for future experiments.展开更多
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 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.
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.
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.
基金supported by the National Natural Science Foundation of China(Nos.11905165,11775081 and 11547044)the Fundamental Research Funds for the Central Universities(Nos.JB160510 and XJS18020).
文摘Based on the beyond-mean-field Skyrme-Hartree-Fock model,impurity effects of theΛhyperon in the hypernuclear systems^(25)ΛMg and^(29)ΛSi are investigated,respectively.Four cases,in which theΛhyperon occupies the single-particle orbitals L[000]1+/2,L[110]1-/2,L[101]3-/2 and L[101]1-/2,are focused.In each case,the potential energy surface and the energy curves projected on certain angular momenta are employed to show the influence of theΛhyperon on the nuclear core.Beside the shrinkage effect that is induced by theΛhyperon occupying the sΛorbital,it is found that theΛhyperon on the pΛorbital,L[110]1-/2,drives the nuclear core toward a prolate shape,while the ones on the other two pΛorbitals,L[101]3-/2 and L[101]1-/2,drive the nuclear core toward an oblate shape.The energy spectra and the corresponding intra-band E2 transition rates for the rotational bands are given as a prediction for future experiments.
