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Yield ratios and directed flows of light particles from proton-rich nuclei-induced collisions

  • Ting-Zhi YanEmail author
  • Shan Li
  • Yan-Nan Wang
  • Fei Xie
  • Ting-Feng Yan
Article
  • 16 Downloads

Abstract

The neutron-to-proton and \({}^3{\hbox {H}}\)-to-\({}^3{\hbox {He}}\) yield ratios, and the directed flows of particles dependent on a reduced rapidity, the transverse momentum per nucleon, and a reduced impact parameter are investigated for \({}^{28}{\hbox {S}} + {}^{28}{\hbox {Si}}\) and \({}^{32}{\hbox {S}} + {}^{28}{\hbox {Si}}\) systems at 50 and 400 MeV/u using an isospin-dependent quantum molecular dynamics model. The results show that these yield ratios of projectile-like fragments are approximately equal to the constituent neutron-to-proton ratio of the projectile. There are clear differences of the directed flows for isospin-related fragments neutron and proton, \({}^3{\hbox {H}}\) and \({}^3{\hbox {He}}\) from \({}^{28}{\hbox {S}} + {}^{28}{\hbox {Si}}\) collisions. The differences in directed flows for neutrons and protons and \({}^3{\hbox {H}}\)\({}^3{\hbox {He}}\) from a proton-rich nucleus \({}^{28}{\hbox {S}}-\) induced collisions are noticeably larger than those from a stable nucleus \({}^{32}{\hbox {S}}-\) induced reactions under medium impact parameters. Thus, the yield ratios and differences in directed flows for the neutrons and protons and \({}^3{\hbox {H}}\)\({}^3{\hbox {He}}\) under medium impact parameters are proposed as possible observable items for studying isospin physics.

Keywords

Yield ratio Directed flow Proton-rich nucleus 

References

  1. 1.
    Z.J. Wang, Z.Z. Ren, Elastic electron scattering on exotic light proton-rich nuclei. Phys. Rev. C 70, 034303 (2004).  https://doi.org/10.1103/PhysRevC.70.034303 CrossRefGoogle Scholar
  2. 2.
    S. Yoshida, H. Sagawa, Neutron skin thickness and equation of state in asymmetric nuclear matter. Phys. Rev. C 69, 024318 (2004).  https://doi.org/10.1103/PhysRevC.69.024318 CrossRefGoogle Scholar
  3. 3.
    A. Bhagwat, Y.K. Gambhir, Recently measured reaction cross sections with low energy fp-shell nuclei as projectiles: microscopic description. Phys. Rev. C 73, 054601 (2006).  https://doi.org/10.1103/PhysRevC.73.054601 CrossRefGoogle Scholar
  4. 4.
    J.G. Chen, X.Z. Cai, H.Y. Zhang et al., Proton halo or skin in the excited states of light nuclei. Chin. Phys. Lett. 20(7), 1021–1024 (2003).  https://doi.org/10.1088/0256-307X/20/7/314 CrossRefGoogle Scholar
  5. 5.
    C.J. Horowitz, S.J. Pollock, P.A. Souder et al., Parity violating measurements of neutron densities. Phys. Rev. C 63, 025501 (2001).  https://doi.org/10.1103/PhysRevC.63.025501 CrossRefGoogle Scholar
  6. 6.
    P. Danielewicz, Surface symmetry energy. Nucl. Phys. A 727, 233 (2005).  https://doi.org/10.1016/j.nuclphysa.2003.08.001 CrossRefGoogle Scholar
  7. 7.
    M. Liu, N. Wang, Z.X. Li et al., Neutron skin thickness of nuclei and effective nucleon–nucleon interactions. Chin. Phys. Lett. 23(4), 804 (2006).  https://doi.org/10.1088/0256-307X/23/4/012 CrossRefGoogle Scholar
  8. 8.
    K. Bennaceur, F. Nowacki, J. Okolowicz et al., Study of the \(^7\)Be(p, y)\(^8\)B and \(^7\)Li(n, y)\(^8\)Li capture reactions using the shell model embedded in the continuum. Nucl. Phys. A 651, 289 (1999).  https://doi.org/10.1016/S0375-9474(99)00133-5 CrossRefGoogle Scholar
  9. 9.
    K. Kaneko, Y. Sun, G. Angelis, Enhancement of high-spin collectivity in N = Z nuclei by the isoscalar neutron–proton pairing. Nucl. Phys. A 957, 144 (2017).  https://doi.org/10.1016/j.nuclphysa.2016.08.007 CrossRefGoogle Scholar
  10. 10.
    Z.H. Sun, Q. Wu, Z.H. Zhao et al., Resonance and continuum Gamow shell model with realistic nuclear forces. Phys. Lett. B 769, 227–232 (2017).  https://doi.org/10.1016/j.physletb.2017.03.054 CrossRefGoogle Scholar
  11. 11.
    I. Tanihata, H. Hamagaki, O. Hashimoto et al., Measurements of interaction cross sections and nuclear radii in the light p-shell region. Phys. Rev. Lett. 55, 2676 (1985).  https://doi.org/10.1103/PhysRevLett.55.2676 CrossRefGoogle Scholar
  12. 12.
    D.Q. Fang, W. Guo, C.W. Ma et al., Examining the exotic structure of the proton-rich nucleus \(^{23}\rm Al\). Phys. Rev. C 76, 031601(R) (2007).  https://doi.org/10.1103/PhysRevC.76.031601 CrossRefGoogle Scholar
  13. 13.
    X.F. Li, D.Q. Fang, Y.G. Ma, Determination of the neutron skin thickness from interaction cross section and chargechanging cross section for B, C, N, O, F isotopes. Nucl. Sci. Tech. 27, 71 (2016).  https://doi.org/10.1007/s41365-016-0064-z CrossRefGoogle Scholar
  14. 14.
    Y.D. Song, H.L. Wei, C.W. Ma et al., Improved FRACS parameterizations for cross sections of isotopes near the proton drip line in projectile fragmentation reactions. Nucl. Sci. Tech. 29, 96 (2018).  https://doi.org/10.1007/s41365-018-0439-4 CrossRefGoogle Scholar
  15. 15.
    B.A. Li, C.M. Ko, Isospin dependence of collective flow. Nucl. Phys. A 654, 797c–802c (1999).  https://doi.org/10.1016/S0375-9474(00)88549-8.CrossRefGoogle Scholar
  16. 16.
    L.W. Chen, F.S. Zhang, Z.Y. Zhu, Isospin effects on rotational flow in intermediate energy heavy ion collisions. Phys. Rev. C 61, 067601 (2000).  https://doi.org/10.1103/PhysRevC.61.067601 CrossRefGoogle Scholar
  17. 17.
    V.N. Russkikh, Y.B. Ivanov, Collective flow in heavy-ion collisions for E\(_{\text{lab}}\) = 1–160 GeV/nucleon. Phys. Rev. C 74, 034904 (2006).  https://doi.org/10.1103/PhysRevC.74.034904 CrossRefGoogle Scholar
  18. 18.
    Z.Q. Feng, Dynamics of strangeness and collective flows in heavy-ion collisions near threshold energies. Nucl. Phys. A 919, 32–45 (2013).  https://doi.org/10.1016/j.nuclphysa.2013.10.005 CrossRefGoogle Scholar
  19. 19.
    H.Y. Zhang, W.Q. Shen, Y.G. Ma et al., Directed and elliptic flows in \(^{40}\)Ca + \(^{40}\)Ca and \(^{112}\)Sn + \(^{112}\)Sn collisions. Eur. Phys. J. A 15, 399–404 (2002).  https://doi.org/10.1140/epja/i2002-10043-7 CrossRefGoogle Scholar
  20. 20.
    S. Gautam, A.D. Sood, R.K. Puri et al., Isospin effects in the disappearance of flow as a function of colliding geometry. Phys. Rev. C 83, 014603 (2011).  https://doi.org/10.1103/PhysRevC.83.014603 CrossRefGoogle Scholar
  21. 21.
    X.Y. Sun, D.Q. Fang, Y.G. Ma et al., Neutron/proton ratio of nucleon emissions as a probe of neutron skin. Phys. Lett. B 682, 396–400 (2010).  https://doi.org/10.1016/j.physletb.2009.11.031 CrossRefGoogle Scholar
  22. 22.
    J.Y. Liu, Q. Zhao, S.J. Wang et al., Entrance channel dependence and isospin dependence of preequilibrium nucleon emission in intermediate energy heavy ion collisions. Nucl. Phys. A 687, 475–485 (2001).  https://doi.org/10.1016/S0375-9474(00)00581-9 CrossRefGoogle Scholar
  23. 23.
    X.C. Zhang, B.A. Li, L.W. Chen et al., Impact parameter dependence of the double neutron/proton ratio of nucleon emissions in isotopic reaction systems. Chin. Phys. Lett. 26(5), 052502 (2009).  https://doi.org/10.1088/0256-307X/26/5/052502 CrossRefGoogle Scholar
  24. 24.
    H.L. Liu, G.C. Yong, D.H. Wen, Probing the momentum dependence of the symmetry potential by the free n/p ratio of pre-equilibrium emission. Phys. Rev. C 91, 024604 (2015).  https://doi.org/10.1103/PhysRevC.91.024604 CrossRefGoogle Scholar
  25. 25.
    D. Theriault, J. Gauthier, F. Grenier et al., Neutron-to-proton ratios of quasiprojectile and midrapidity emission in the \(^{64}\)Zn + \(^{64}\)Zn reaction at 45 MeV/nucleon. Phys. Rev. C 74, 051602(R) (2006).  https://doi.org/10.1103/PhysRevC.74.051602 CrossRefGoogle Scholar
  26. 26.
    Y.X. Zhang, M.B. Tsang, Z.X. Li et al., Constraints on nucleon effective mass splitting with heavy ion collisions. Phys. Lett. B 732, 186–190 (2014).  https://doi.org/10.1016/j.physletb.2014.03.030 MathSciNetCrossRefGoogle Scholar
  27. 27.
    W.J. Xie, J. Su, L. Zhu et al., Neutron–proton effective mass splitting in a Boltzmann–Langevin approach. Phys. Rev. C 88, 061601(R) (2013).  https://doi.org/10.1103/PhysRevC.88.061601 CrossRefGoogle Scholar
  28. 28.
    J. Su, L. Zhu, C.Y. Huang et al., Correlation between symmetry energy and effective \(\kappa\)-mass splitting with an improved isospin- and momentum-dependent interaction. Phys. Rev. C 94, 034619 (2016).  https://doi.org/10.1103/PhysRevC.94.034619 CrossRefGoogle Scholar
  29. 29.
    M. Yu, K.J. Duan, S.S. Wang et al., A nuclear density probe: isobaric yield ratio difference. Nucl. Sci. Tech. 26, S20503 (2015).  https://doi.org/10.13538/j.1001-8042/nst.26.S20503 CrossRefGoogle Scholar
  30. 30.
    B.A. Li, B.J. Cai, L.W. Chen et al., Isospin dependence of nucleon effective masses in neutron-rich matter. Nucl. Sci. Tech. 27, 141 (2016).  https://doi.org/10.1007/s41365-016-0140-4 CrossRefGoogle Scholar
  31. 31.
    J. Aichelin, “Quantum” molecular dynamics: a dynamical microscopic n-body approach to investigate fragment formation and the nuclear equation of state in heavy ion collisions. Phys. Rep. 202, 233–360 (1991).  https://doi.org/10.1016/0370-1573(91)90094-3 CrossRefGoogle Scholar
  32. 32.
    L.W. Chen, F.S. Zhang, G.M. Jin, Analysis of isospin dependence of nuclear collective flow in an isospin-dependent quantum molecular dynamics model. Phys. Rev. C 58, 2283 (1998).  https://doi.org/10.1103/PhysRevC.58.2283 CrossRefGoogle Scholar
  33. 33.
    Y.G. Ma, W.Q. Shen, Z.Y. Zhu, Collective motion of reverse-reaction system in the intermediate-energy domain via the quantum-molecular-dynamics approach. Phys. Rev. C 51, 1029 (1995).  https://doi.org/10.1103/PhysRevC.51.1029 CrossRefGoogle Scholar
  34. 34.
    Y.X. Zhang, Z.X. Li, C.S. Zhou et al., Effect of isospin-dependent cluster recognition on the observables in heavy ion collisions. Phys. Rev. C 85, 051602(R) (2012).  https://doi.org/10.1103/PhysRevC.85.051602 CrossRefGoogle Scholar
  35. 35.
    G.A. Lalazissis, A.R. Farhan, M.M. Sharma, Light nuclei near neutron and proton drip lines in relativistic mean-field theory. Nucl. Phys. A 628, 221–254 (1998).  https://doi.org/10.1016/S0375-9474(97)00630-1 CrossRefGoogle Scholar

Copyright information

© China Science Publishing & Media Ltd. (Science Press), Shanghai Institute of Applied Physics, the Chinese Academy of Sciences, Chinese Nuclear Society and Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  • Ting-Zhi Yan
    • 1
    Email author
  • Shan Li
    • 1
  • Yan-Nan Wang
    • 1
  • Fei Xie
    • 1
  • Ting-Feng Yan
    • 2
  1. 1.School of Energy and Power EngineeringNortheast Electric Power UniversityJilinChina
  2. 2.State Grid Tancheng Power Supply CompanyLinyiChina

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