The dissipation phenomenon in the heavy-ion reaction at incident energy near the Fermi energy is studied by simulating the reaction ^129Xe＋^129Sn with the isospin-dependent quantum molecular dynamics model. The calcu...The dissipation phenomenon in the heavy-ion reaction at incident energy near the Fermi energy is studied by simulating the reaction ^129Xe＋^129Sn with the isospin-dependent quantum molecular dynamics model. The calculations involving a proper prescription of implementing the Pauli exclusion principle show that the isotropy ratio measured by free protons emitted in the reaction at energy slightly higher than the Fermi energy is in agreement with the experimental data recently released by the INDRA collaboration. A feasible value of the Pauli-blocking factor is estimated by comparing the theoretical results with the experimental data for the energy range considered here.展开更多
Three typical Pauli blocking algorithms in quantum molecular dynamics type models are investigated in the nuclear matter,the nucleus,and heavy ion collisions.In nuclear matter,the blocking ratios obtained with the thr...Three typical Pauli blocking algorithms in quantum molecular dynamics type models are investigated in the nuclear matter,the nucleus,and heavy ion collisions.In nuclear matter,the blocking ratios obtained with the three algorithms are underestimated by 13%-25%compared to the corresponding analytical values.For a finite nucleus,spurious collisions occur around the surface of the nucleus owing to the defects of the Pauli blocking algorithms.In the simulations of heavy ion collisions,the uncertainty of stopping power arising from the different Pauli blocking algorithms is less than 5%.Furthermore,the in-medium effects of nucleon-nucleon(NN)cross sections on the nuclear stopping power are discussed.Our results show that the transport model calculations with free NN cross sections result in the stopping power decreasing with beam energy when the beam energy is less than 300 MeV/u.To increase or decrease the values of the stopping power,the transport model calculations need enhanced or suppressed model dependent in-medium NN cross sections that are expected to be smaller than the true in-medium NN cross sections.展开更多
In this study,the Pauli blocking potential between two colliding nuclei in the density overlapping regionis applied to describe the heavy nuclei fusion process.Inspired by the Pauli blocking effect in theα-decay of h...In this study,the Pauli blocking potential between two colliding nuclei in the density overlapping regionis applied to describe the heavy nuclei fusion process.Inspired by the Pauli blocking effect in theα-decay of heavynuclei,the Pauli blocking potential of single nucleon from the surrounding matter is obtained.In fusion reactionswith strong density overlap,the Pauli blocking potential between the projectile and target can be constructed using asingle folding model.By considering this potential,the double folding model with a new parameter set is employedto analyze the fusion processes of 95 systems.A wider Coulomb barrier and shallower potential pocket are formed inthe inner part of the potential between the two colliding nuclei,compared to that calculated using the Akyüz-Win-ther potential.The fusion hindrance phenomena at deep sub-barrier energies are described well for fusion systems^(16)O+^(208)Pb and^(58)Ni+^(58)Ni.展开更多
In order to investigate the elastic scattering,we fit scattering observables of the weighted fits(WF16)with the relativistic Love-Franey(RLF)model.The masses,cutoff parameters,and initial coupling strengths of RLF are...In order to investigate the elastic scattering,we fit scattering observables of the weighted fits(WF16)with the relativistic Love-Franey(RLF)model.The masses,cutoff parameters,and initial coupling strengths of RLF are assumed to be independent of energy.Because the energy boundary between low energy and high energy is around 200 Me V,the masses,cutoff parameters,and initial coupling strengths of RLF are obtained by fitting scattering observables of WF16 at an incident energy of 200 MeV.With the masses,cutoff parameters,and initial coupling strengths as the input,the energy-dependent RLF model is constructed over the laboratory energy range of 20 to 800MeV within a unified fit.To examine the validity of this fit,we investigate p+^(208)Pbelastic scattering for various energies.Although the scattering observables of pp and pn of 200 MeV best fit the values of WF16,the RLF model of 200 MeV without the Pauli blocking(PB)corrections fails to describe the experimental differential cross sections,analyzing powers,and spinrotation functions.When the PB corrections are taken into account for various energies,the RLF model can well describe the experimental data of p+^(208)Pbelastic scattering.展开更多
基金Supported by the National Natural Science Foundation Of China under Grant Nos 11265013,11175074,11264033 and 11464040
文摘The dissipation phenomenon in the heavy-ion reaction at incident energy near the Fermi energy is studied by simulating the reaction ^129Xe＋^129Sn with the isospin-dependent quantum molecular dynamics model. The calculations involving a proper prescription of implementing the Pauli exclusion principle show that the isotropy ratio measured by free protons emitted in the reaction at energy slightly higher than the Fermi energy is in agreement with the experimental data recently released by the INDRA collaboration. A feasible value of the Pauli-blocking factor is estimated by comparing the theoretical results with the experimental data for the energy range considered here.
基金This work was partly inspired by the transport code comparison project,and it was supported by the National Natural Science Foundation of China(11875323,11705163,11790320,11790323,11961141003)the National Key R&D Program of China(2018YFA0404404)+1 种基金the Continuous Basic Scientific Research Project(WDJC-2019-13,BJ20002501)the funding of China Institute of Atomic Energy。
文摘Three typical Pauli blocking algorithms in quantum molecular dynamics type models are investigated in the nuclear matter,the nucleus,and heavy ion collisions.In nuclear matter,the blocking ratios obtained with the three algorithms are underestimated by 13%-25%compared to the corresponding analytical values.For a finite nucleus,spurious collisions occur around the surface of the nucleus owing to the defects of the Pauli blocking algorithms.In the simulations of heavy ion collisions,the uncertainty of stopping power arising from the different Pauli blocking algorithms is less than 5%.Furthermore,the in-medium effects of nucleon-nucleon(NN)cross sections on the nuclear stopping power are discussed.Our results show that the transport model calculations with free NN cross sections result in the stopping power decreasing with beam energy when the beam energy is less than 300 MeV/u.To increase or decrease the values of the stopping power,the transport model calculations need enhanced or suppressed model dependent in-medium NN cross sections that are expected to be smaller than the true in-medium NN cross sections.
基金Supported by the National Natural Science Foundation of China(12105080,11822503,11975091)the Program for Innovative Research Team(in Science and Technology)in University of Henan Province(21IRTSTHN011),China。
文摘In this study,the Pauli blocking potential between two colliding nuclei in the density overlapping regionis applied to describe the heavy nuclei fusion process.Inspired by the Pauli blocking effect in theα-decay of heavynuclei,the Pauli blocking potential of single nucleon from the surrounding matter is obtained.In fusion reactionswith strong density overlap,the Pauli blocking potential between the projectile and target can be constructed using asingle folding model.By considering this potential,the double folding model with a new parameter set is employedto analyze the fusion processes of 95 systems.A wider Coulomb barrier and shallower potential pocket are formed inthe inner part of the potential between the two colliding nuclei,compared to that calculated using the Akyüz-Win-ther potential.The fusion hindrance phenomena at deep sub-barrier energies are described well for fusion systems^(16)O+^(208)Pb and^(58)Ni+^(58)Ni.
基金Supported by the National Natural Science Foundation of China(12175072,11722546,12147106)。
文摘In order to investigate the elastic scattering,we fit scattering observables of the weighted fits(WF16)with the relativistic Love-Franey(RLF)model.The masses,cutoff parameters,and initial coupling strengths of RLF are assumed to be independent of energy.Because the energy boundary between low energy and high energy is around 200 Me V,the masses,cutoff parameters,and initial coupling strengths of RLF are obtained by fitting scattering observables of WF16 at an incident energy of 200 MeV.With the masses,cutoff parameters,and initial coupling strengths as the input,the energy-dependent RLF model is constructed over the laboratory energy range of 20 to 800MeV within a unified fit.To examine the validity of this fit,we investigate p+^(208)Pbelastic scattering for various energies.Although the scattering observables of pp and pn of 200 MeV best fit the values of WF16,the RLF model of 200 MeV without the Pauli blocking(PB)corrections fails to describe the experimental differential cross sections,analyzing powers,and spinrotation functions.When the PB corrections are taken into account for various energies,the RLF model can well describe the experimental data of p+^(208)Pbelastic scattering.
