中国物理B ›› 2007, Vol. 16 ›› Issue (9): 2676-2682.doi: 10.1088/1009-1963/16/9/031

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Scaling of anisotropic flows and nuclear equation of state in intermediate energy heavy ion collisions

马余刚1, 蔡翔舟1, 方德清1, 马春旺1, 田文栋1, 王鲲1, 颜廷志2, 郭威2, 沈文庆2   

  1. (1)Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China; (2)Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China;Graduate School of the Chinese Academy of Sciences,Beijing 100039, China
  • 收稿日期:2006-12-26 修回日期:2007-07-04 出版日期:2007-09-20 发布日期:2007-09-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10535010 and 10610285), the Shanghai Development Foundation for Science and Technology of China (Grant Nos~06JC14082 and 05XD14021), and Chinese Academy of Sciences project (Grant No~KJCX3.SYW.N2).

Scaling of anisotropic flows and nuclear equation of state in intermediate energy heavy ion collisions

Yan Ting-Zhi(颜廷志)a)b), Ma Yu-Gang(马余刚)a)†, Cai Xiang-Zhou(蔡翔舟)a), Fang De-Qing(方德清)a), Guo Wei(郭威)a)b), Ma Chun-Wang(马春旺)a)b), Shen Wen-Qing(沈文庆)a), Tian Wen-Dong(田文栋)a), and Wang Kun(王鲲)a)   

  1. a Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China; b Graduate School of the Chinese Academy of Sciences, Beijing 100039, China
  • Received:2006-12-26 Revised:2007-07-04 Online:2007-09-20 Published:2007-09-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10535010 and 10610285), the Shanghai Development Foundation for Science and Technology of China (Grant Nos~06JC14082 and 05XD14021), and Chinese Academy of Sciences project (Grant No~KJCX3.SYW.N2).

摘要: Elliptic flow ($v_2$) and hexadecupole flow ($v_4$) of light clusters have been studied in detail for 25 MeV/nucleon $^{86}$Kr + $^{124}$Sn at large impact parameters by using a quantum molecular dynamics model with different potential parameters. Four sets of parameters including soft or hard equation of state (EOS) with or without symmetry energy term are used. Both number-of-nucleon ($A$) scaling of the elliptic flow versus transverse momentum ($p_{\rm t}$) and the scaling of $v_4/A^{2}$ versus $(p_{\rm t}/A)^2$ have been demonstrated for the light clusters in all above calculation conditions. It is also found that the ratio of $v_4/{v_2}^2$ maintains a constant of 1/2 which is independent of $p_{\rm t}$ for all the light fragments. Comparisons among different combinations of the EOS and the symmetry potential term show that the above scaling behaviours are sound and independent of the details of potential, while the strengths of flows are sensitive to the EOS and the symmetry potential term.

关键词: anisotropic flow, number-of-nucleon scaling, EOS, symmetry energy

Abstract: Elliptic flow ($v_2$) and hexadecupole flow ($v_4$) of light clusters have been studied in detail for 25 MeV/nucleon $^{86}$Kr + $^{124}$Sn at large impact parameters by using a quantum molecular dynamics model with different potential parameters. Four sets of parameters including soft or hard equation of state (EOS) with or without symmetry energy term are used. Both number-of-nucleon ($A$) scaling of the elliptic flow versus transverse momentum ($p_{\rm t}$) and the scaling of $v_4/A^{2}$ versus $(p_{\rm t}/A)^2$ have been demonstrated for the light clusters in all above calculation conditions. It is also found that the ratio of $v_4/{v_2}^2$ maintains a constant of 1/2 which is independent of $p_{\rm t}$ for all the light fragments. Comparisons among different combinations of the EOS and the symmetry potential term show that the above scaling behaviours are sound and independent of the details of potential, while the strengths of flows are sensitive to the EOS and the symmetry potential term.

Key words: anisotropic flow, number-of-nucleon scaling, EOS, symmetry energy

中图分类号:  (Nuclear matter)

  • 21.65.-f
21.60.Gx (Cluster models) 25.75.-q (Relativistic heavy-ion collisions (collisions induced by light ions studied to calibrate relativistic heavy-ion collisions should be classified under both 25.75.-q and sections 13 or 25 appropriate to the light ions)) 27.60.+j (90 ≤ A ≤ 149)