Recent progress of the quantum molecular dynamics model for describing the dynamics of heavy-ion collisions is viewed, in particular the nuclear fragmentation, isospin physics, particle production and in-medium effect...Recent progress of the quantum molecular dynamics model for describing the dynamics of heavy-ion collisions is viewed, in particular the nuclear fragmentation, isospin physics, particle production and in-medium effect, hadron-induced nuclear reactions, hypernucleus, etc.The neck fragmentation in Fermi-energy heavy-ion collisions is investigated for extracting the symmetry energy at subsaturation densities. The isospin effects, in-medium properties, and the behavior of high-density symmetry energy in medium-and high-energy heavy-ion collisions are thoroughly discussed. The hypernuclide dynamics formed in heavy-ion collisions and in hadron-induced reactions is analyzed and addressed in the future experiments at the high-intensity heavy-ion accelerator facility(HIAF).展开更多
Reaction dynamics in collisions of antiprotons on nuclei is investigated within the Lanzhou quantum molecular dynamics model. The reaction channels of elastic scattering, annihilation, charge exchange and inelastic co...Reaction dynamics in collisions of antiprotons on nuclei is investigated within the Lanzhou quantum molecular dynamics model. The reaction channels of elastic scattering, annihilation, charge exchange and inelastic collisions of antiprotons on nucleons have been included in the model. Dynamics on particle production, in particular pions, kaons, antikaons and hyperons, is investigated in collisions of p on12 C,20Ne,40 Ca and181Ta from low to high incident momenta. It is found that the annihilations of p on nucleons are of importance to the dynamics of particle production in phase space. Hyperons are mainly produced via meson induced reactions on nucleons and strangeness exchange collisions, which lead to delayed emission in antiproton-nucleus collisions.展开更多
The dynamics of the η meson produced in proton-induced nuclear reactions via the decay of N*(1535)has been investigated within the Lanzhou quantum molecular dynamics transport model.The in-medium modifications of the...The dynamics of the η meson produced in proton-induced nuclear reactions via the decay of N*(1535)has been investigated within the Lanzhou quantum molecular dynamics transport model.The in-medium modifications of the η production in dense nuclear matter are included in the model,in which an attractive η-nucleon potential is implemented.The impact of the η optical potential on the η dynamics is investigated.It is found that the attractive potential leads to the reduction in high-momentum(kinetic energy) production from the spectra of momentum distributions and inclusive cross sections and increasing the reabsorption process by surrounding nucleons.展开更多
Within the framework of the Lanzhou quantum molecular dynamics model,the deep subthreshold antiproton production in heavy-ion collisions has been investigated thoroughly.The elastic scattering,annihilation and charge ...Within the framework of the Lanzhou quantum molecular dynamics model,the deep subthreshold antiproton production in heavy-ion collisions has been investigated thoroughly.The elastic scattering,annihilation and charge exchange reactions associated with antiproton channels are implemented in the model.The attractive antiproton potential extracted from the G-parity transformation of nucleon selfenergies reduces the threshold energies in meson-baryon and baryon-baryon collisions,and consequently enhances the antiproton yields to some extent.The calculated invariant spectra are consistent with the available experimental data.The primordial antiproton yields increase with the mass number of the colliding system.However,annihilation reactions reduce the antiproton production which becomes independent of the colliding partners.Anti-flow phenomena of antiprotons correlated with the mean field potential and annihilation mechanism is found by comparing them with the proton flows.Possible experiments at the high-intensity heavy-ion accelerator facility(HIAF) in China are discussed.展开更多
The isospin effect in peripheral heavy-ion collisions was thoroughly investigated within the framework of the Lanzhou quantum molecular dynamics (LQMD) transport model. A coalescence approach was used to recognize t...The isospin effect in peripheral heavy-ion collisions was thoroughly investigated within the framework of the Lanzhou quantum molecular dynamics (LQMD) transport model. A coalescence approach was used to recognize the primary fragments formed in nucleus-nucleus collisions. described using the statistical code GEMINI. The production The secondary decay process of these fragments was mechanism and isospin effect of the projectile-like and target-like fragments were analyzed using the combined approach. It was found that the isospin migration from the high-isospin density to the low-density matter occurred in the neutron-rich nuclear reactions, i.e., ^48Ca+^208Pb, ^86Kr+^48SCa/^208Pb/^124Sn,^136Xe+^208Pb, ^124Sn+^124Sn, and ^136Xe+^136Xe. A hard symmetry energy was available for creating the neutron-rich fragments, particularly in the medium-mass region. The isospin effect of the neutron-to- proton (n/p) ratio of the complex fragments was reduced when the secondary decay process was included. However, a soft symmetry energy enhanced the n/p ratio of the light particles, particularly at kinetic energies greater than 15 MeV/nucleon.展开更多
The dynamics of high-energy proton-induced spallation reactions on target nuclides of 56Fe,58Ni,107Ag,112d,184W,181Ta,197Au,and 208Pb are investigated with the quantum molecular dynamics transport model motivated by t...The dynamics of high-energy proton-induced spallation reactions on target nuclides of 56Fe,58Ni,107Ag,112d,184W,181Ta,197Au,and 208Pb are investigated with the quantum molecular dynamics transport model motivated by the China initiative Accelerator Driven System(CiADS)in Huizhou and the China Spallation Neutron Source(CSNS)in Dongguan.The production mechanism of light nuclides and fission fragments is thoroughly analyzed,and the results obtained thereby are compared with available experimental data.The statistical code GEMINI is employed in conjunction with a transport model for describing the decay of primary fragments.For the treatment of cluster emission during the preequilibrium stage,a surface coalescence model is implemented into the model.It is found that the available data in terms of total fragment yields are well reproduced in the combined approach for spallation reactions both on the heavy and light targets.The energetic light nuclides(deuteron,triton,helium isotopes etc)mainly created during the preequilibrium stage are treated within the framework of surface coalescence,whereas their evaporation is described in the conventional manner by the GEMINI code.With this combined approach,a good overall description of light clusters and neutron emission is obtained,and some discrepancies with the experimental data are discussed.Possible production of radioactive isotopes in the spallation reactions is also analyzed,i.e.,the 6.8He energy spectra.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11675226 and 11722546)the Major State Basic Research Development Program of China(Nos.2014CB845405 and 2015CB856903)
文摘Recent progress of the quantum molecular dynamics model for describing the dynamics of heavy-ion collisions is viewed, in particular the nuclear fragmentation, isospin physics, particle production and in-medium effect, hadron-induced nuclear reactions, hypernucleus, etc.The neck fragmentation in Fermi-energy heavy-ion collisions is investigated for extracting the symmetry energy at subsaturation densities. The isospin effects, in-medium properties, and the behavior of high-density symmetry energy in medium-and high-energy heavy-ion collisions are thoroughly discussed. The hypernuclide dynamics formed in heavy-ion collisions and in hadron-induced reactions is analyzed and addressed in the future experiments at the high-intensity heavy-ion accelerator facility(HIAF).
基金Supported by the Major State Basic Research Development Program in China(Nos.2014CB845405 and 2015CB856903)the National Natural Science Foundation of China Projects(Nos.11175218 and U1332207)the Youth Innovation Promotion Association of Chinese Academy of Sciences
文摘Reaction dynamics in collisions of antiprotons on nuclei is investigated within the Lanzhou quantum molecular dynamics model. The reaction channels of elastic scattering, annihilation, charge exchange and inelastic collisions of antiprotons on nucleons have been included in the model. Dynamics on particle production, in particular pions, kaons, antikaons and hyperons, is investigated in collisions of p on12 C,20Ne,40 Ca and181Ta from low to high incident momenta. It is found that the annihilations of p on nucleons are of importance to the dynamics of particle production in phase space. Hyperons are mainly produced via meson induced reactions on nucleons and strangeness exchange collisions, which lead to delayed emission in antiproton-nucleus collisions.
基金supported by the Major State Basic Research Development Program in China(No.2014CB845405)the National Natural Science Foundation of China Projects(Nos.11175218,U1332207 and U1432247)the Youth Innovation Promotion Association of Chinese Academy of Sciences,and the Scientific Research Program of Shanxi Provincial Education Department(No.14JK1794)
文摘The dynamics of the η meson produced in proton-induced nuclear reactions via the decay of N*(1535)has been investigated within the Lanzhou quantum molecular dynamics transport model.The in-medium modifications of the η production in dense nuclear matter are included in the model,in which an attractive η-nucleon potential is implemented.The impact of the η optical potential on the η dynamics is investigated.It is found that the attractive potential leads to the reduction in high-momentum(kinetic energy) production from the spectra of momentum distributions and inclusive cross sections and increasing the reabsorption process by surrounding nucleons.
基金Supported by the National Natural Science Foundation of China under Grant(11722546 and 11675226)the Talent Program of South China University of Technology
文摘Within the framework of the Lanzhou quantum molecular dynamics model,the deep subthreshold antiproton production in heavy-ion collisions has been investigated thoroughly.The elastic scattering,annihilation and charge exchange reactions associated with antiproton channels are implemented in the model.The attractive antiproton potential extracted from the G-parity transformation of nucleon selfenergies reduces the threshold energies in meson-baryon and baryon-baryon collisions,and consequently enhances the antiproton yields to some extent.The calculated invariant spectra are consistent with the available experimental data.The primordial antiproton yields increase with the mass number of the colliding system.However,annihilation reactions reduce the antiproton production which becomes independent of the colliding partners.Anti-flow phenomena of antiprotons correlated with the mean field potential and annihilation mechanism is found by comparing them with the proton flows.Possible experiments at the high-intensity heavy-ion accelerator facility(HIAF) in China are discussed.
基金Supported by the National Natural Science Foundation of China(11722546,11675226)the Talent Program of South China University of Technology(K5180470)
文摘The isospin effect in peripheral heavy-ion collisions was thoroughly investigated within the framework of the Lanzhou quantum molecular dynamics (LQMD) transport model. A coalescence approach was used to recognize the primary fragments formed in nucleus-nucleus collisions. described using the statistical code GEMINI. The production The secondary decay process of these fragments was mechanism and isospin effect of the projectile-like and target-like fragments were analyzed using the combined approach. It was found that the isospin migration from the high-isospin density to the low-density matter occurred in the neutron-rich nuclear reactions, i.e., ^48Ca+^208Pb, ^86Kr+^48SCa/^208Pb/^124Sn,^136Xe+^208Pb, ^124Sn+^124Sn, and ^136Xe+^136Xe. A hard symmetry energy was available for creating the neutron-rich fragments, particularly in the medium-mass region. The isospin effect of the neutron-to- proton (n/p) ratio of the complex fragments was reduced when the secondary decay process was included. However, a soft symmetry energy enhanced the n/p ratio of the light particles, particularly at kinetic energies greater than 15 MeV/nucleon.
基金National Natural Science Foundation of China(11175218,10805061)Youth Innovation Promotion Association of Chinese Academy of SciencesKnowledge Innovation Project of Chinese Academy of Sciences(KJCX2-EW-N01)~~
基金National Natural Science Foundation of China(11675226,11175218)National Basic Research Program of China(973 Program)(2015CB856903)Youth Innovation Promotion Association of Chinese Academy of Sciences~~
基金Supported by the National Natural Science Foundation of China(11722546,11675226)the Talent Program of South China University of Technology。
文摘The dynamics of high-energy proton-induced spallation reactions on target nuclides of 56Fe,58Ni,107Ag,112d,184W,181Ta,197Au,and 208Pb are investigated with the quantum molecular dynamics transport model motivated by the China initiative Accelerator Driven System(CiADS)in Huizhou and the China Spallation Neutron Source(CSNS)in Dongguan.The production mechanism of light nuclides and fission fragments is thoroughly analyzed,and the results obtained thereby are compared with available experimental data.The statistical code GEMINI is employed in conjunction with a transport model for describing the decay of primary fragments.For the treatment of cluster emission during the preequilibrium stage,a surface coalescence model is implemented into the model.It is found that the available data in terms of total fragment yields are well reproduced in the combined approach for spallation reactions both on the heavy and light targets.The energetic light nuclides(deuteron,triton,helium isotopes etc)mainly created during the preequilibrium stage are treated within the framework of surface coalescence,whereas their evaporation is described in the conventional manner by the GEMINI code.With this combined approach,a good overall description of light clusters and neutron emission is obtained,and some discrepancies with the experimental data are discussed.Possible production of radioactive isotopes in the spallation reactions is also analyzed,i.e.,the 6.8He energy spectra.