Yong-Zhong Xing

Publications (8)0 Total impact

• Source

  Available from: arxiv.org

  Article: Isospin fractionation in the nucleon emissions and fragment emissions in the intermediate energy heavy ion collisions

  Jian-Ye Liu, Wen-Jun Guo, Yong-Zhong Xing, Hang Liu
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  ABSTRACT: The degree of isospin fractionation is measured by $(N/Z)_{n}$ / $(N/Z)_{N_{imf}}$, where $(N/Z)_{n}$ and $(N/Z)_{N_{imf}}$ are the saturated neutron-proton ratio of nucleon emissions (gas phase) and that of fragment emissions (liquid phase) in heavy ion collision at intermediate energy . The calculated results by using the isospin-dependent quantum molecular dynamics model show that the degree of isospin fractionation is sensitive to the neutron-proton ratio of colliding system but insensitive to the difference between the neutron-proton ratio of target and that of projectile. In particular, the degree of isospin fractionation sensitively depends on the symmetry potential. However its dependences on the isospin dependent in-medium nucleon-nucleon cross section and momentum dependent interaction are rather weak. The nucleon emission (gas phase) mainly determines the dynamical behavior of the degree of isospin fractionation in the isospin fractionation process, compared to the effect of fragment emission. In this case, we propose that $(N/Z)_{n}$ / $(N/Z)_{N_{imf}}$ or $(N/Z)_{n}$ can be directly compared with the experimental data so that the information about symmetry potential can be obtained
  07/2003;
• Source

  Available from: ArXiv

  Article: Influence of medium correction of nucleon nucleon cross section on the fragmentation and nucleon emission

  Yong-Zhong Xing, Jian-Ye Liu, Wen-Jun Guo
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  ABSTRACT: The influence of medium correction from an isospin dependent nucleon nucleon cross section on the fragmentation and nucleon emission in the intermediate energy heavy ion collisions was studied by using an isospin dependent quantum molecular dynamical model (IQMD). We found that the medium correction enhances the dependence of multiplicity of intermediate mass fragment $N_{imf}$ and the number of nucleon emission $N_{n}$ on the isospin effect of the nucleon nucleon cross section,while the momentum dependent interaction (MDI) produces also an important role for enhancing the influence of the medium correction on the isospin dependence of two-body collision in the fragmentation and nucleon emission processes. After considering the medium correction and the role of momentum dependent interaction the increase for the dependence of $N_{imf}$ and $N_{n}$ on the isospin effect of two-body collision is favorable to learn the information about the isospin dependent nucleon nucleon cross section Comment: 7 figures
  07/2003;
• Source

  Available from: arxiv.org

  Article: Medium influence of the nucleon nucleon cross section on the fragmentation

  Jian-Ye Liu, Yong-Zhong Xing, Wen-Jun Guo
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  ABSTRACT: Based on an isospin dependent quantum molecular dynamics model we studied the influence of a medium correction of an isospin dependent nucleon nucleon cross section on the fragmentation at the intermediate energy heavy ion collisions. We found that the medium correction from an isospin dependent nucleon nucleon cross section increases the dependence of the fragmentation on the isospin effect of in-medium nucleon nucleon cross section, at the same time, the momentum dependent interaction (MDI) produces also an important role for enhancing the influence of the medium correction on the isospin effect of two-body collisions in the fragmentation process. In this case, the dependence of the multiplicity of intermediate mass fragments $N_{imf}$ on the isospin effect of two-body collision due to the medium correction and MDI, is a probe for extracting the information on the isospin dependent nucleon cnucleon cross section in the medium correction. Comment: 4 pages,3 figures
  07/2003;
• Source

  Available from: arxiv.org

  Article: Probing the isospin dependent mean field and nucleon nucleon cross section in the medium by the nucleon emissions

  Jian-Ye Liu, Yong-Zhong Xing, Wen-Jun Guo
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  ABSTRACT: We study the isospin effects of the mean field and two-body collision on the nucleon emissions at the intermediate energy heavy ion collisions by using an isospin dependent transport theory. The calculated results show that the nucleon emission number $N_{n}$ depends sensitively the isospin effect of nucleon nucleon cross section and weakly on the isospin dependent mean field for neutron-poor system in higher beam energy region . In particular, the correlation between the medium correction of two-body collision and the momentum dependent interaction enhances the dependence of nucleon emission number $N_{n}$ on the isospin effect of nucleon nucleon cross section. On the contrary, the ratio of the neutron proton ratio of the gas phase to the neutron proton ratio of the liquid phase, i.e., the degree of isospin fractionation $<(N/Z)_{gas}>_{b}/<(N/Z)_{liq}>_{b}$ depends sensitively on the isospin dependent mean field and weakly on the isospin effect of two-body collision for neutron-rich system in the lower beam energy region. In this case, $N_{n}$ and $<(N/Z)_{gas}>_{b}/<(N/Z)_{liq}>_{b}$ are the probes for extracting the information about the isospin dependent nucleon nucleon cross section in the medium and the isospin dependent mean field,respectively. Comment: 4 pages,4 figures
  07/2003;
• Source

  Available from: arxiv.org

  Article: Influence of a momentum dependent interaction on the isospin dependence of fragmentation and dissipation in intermediate energy heavy ion collisions

  Jian-Ye Liu, Wen-Jun Guo, Yong-Zhong Xing, Wei Zou, Xi-Guo Lee
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  ABSTRACT: We studied the influence of a momentum dependent interaction in the context of isopspin effects on fragmentation and dissipation in intermediate energy heavy ion collisions by using an isospin dependent quantum molecular dynamics model. It is shown that the nuclear stopping, the number of nucleons emitted ,and the multiplicity of intermediate mass fragments are larger with a momentum dependent interaction than without. In particular, the differences for these observables, when using an isospin dependent in-medium nucleon nucleon cross section versus an isospin independent one, are also larger at high energies for a momentum dependent interaction than without one. Therefore,momentum dependence enhances the sensitivities of those observables to the isospin effect of the in-medium nucleon nucleon cross section towards high beam energies Comment: 6 pages,3 figures
  05/2003;
• Source

  Available from: arxiv.org

  Article: Probing the isospin dependent in-medium nucleon–nucleon cross section by nucleon emissions

  Jian-Ye Liu, Wen-Jun Guo, Yong-Zhong Xing, Wei Zuo, Xi-Guo Lee, Zeng-Hua Li
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  ABSTRACT: The effects of the symmetry potential and the isospin dependent in-medium nucleon–nucleon (NN) cross section on the number of proton(neutron) emissions Np(Nn) are studied respectively within an isospin-dependent quantum molecular dynamics (IQMD) model. The isospin dependent in-medium NN cross section is found to have a strong influence on Np(Nn) but Np(Nn) is not sensitive to the symmetry potential for the neutron-deficient colliding system at relatively high energies. We propose to make use of the Np(Nn) as a probe to extract information on the isospin dependent in-medium NN cross section.
  Physics Letters B.
• Article: Special roles of loose neutron-halo nucleus structure on the fragmentation and momentum dissipation in heavy ion collisions

  Jian Ye Liu, Wen Jun Guo, Zhong Zhou Ren, Yong Zhong Xing, Wen Zuo, Xi Guo Lee
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  ABSTRACT: We studied the special roles of loose neutron-halo structure of 19B on the fragmentation and momentum dissipation by using isospin dependent quantum molecular dynamics. In order to protrude the special roles of neutron-halo structure on the reaction dynamics we compared the fragmentation multiplicity and nuclear stopping (momentum dissipations) induced by neutron-halo nucleus 19B with those induced by a same mass stable nucleus 19F under the same incident channel condition. We found that the loose neutron-halo structure of 19B increases the fragmentation multiplicity in lower beam energy region. On the contrary, the special halo structure of 19B weakens the nuclear stopping, compared to those induced by stable nucleus 19F. However both fragmentation multiplicity-difference and nuclear stopping-difference between the reactions induced by 19B and 19F gradually decrease and finally disappear as the increase of beam energy. These results suggest a good project for the experimental measurements of the fragmentation multiplicity and nuclear stopping to study the reaction dynamics induced by neutron-halo nuclei.
  Physics Letters B. 617:24-32.
• Article: Isospin effect of Coulomb interaction on the dissipation and fragmentation in intermediate energy heavy ion collisions

  Jian-Ye Liu, Wen-Jun Guo, Yong Zhong Xing, Xi Guo Li, Yuan Yi Gao
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  ABSTRACT: We investigate separately the isospin effects of Coulomb interaction and symmetry potential on the dissipation and fragmentation in the intermediate energy heavy ion collisions by using isospin-dependent quantum molecular dynamics model. The calculated results show that the Coulomb interaction induces the reductions of both isospin fractionation ratio and nuclear stopping (momentum dissipation). However, the Coulomb interaction not only does not change obviously the strong isospin effect of the symmetry potential on the isospin fractionation ratio but also does not change obviously that of in-medium two-body collision on the nuclear stopping. On the contrary, the symmetry potential induces the enhancement of the isospin fractionation ratio but it is insensitive to the nuclear stopping. Finally, the competition between the Coulomb interaction and symmetry potential induces the reductions of both isospin fractionation ratio and nuclear stopping for two forms of symmetry potentials in this paper.
  Phys. Rev. C. 70(3).