Impact parameter dependence of the yield ratios of light particles as a probe of neutron skin
Abstract
The yield ratios of neutron/proton (R(n/p)) and \({^3}\hbox {H}/{^3}{\text{He}}\) (\(R(t/{^3}{\mathrm{He}})\)) with reduced rapidity from 0 to 0.5 are investigated for 50 MeV/u \({^{42,44,46,48,50,52,54,56}}{\text{Ca}} + {^{40}}{\text{Ca}}\). This was conducted at whole reduced impact parameters using the isospin-dependent quantum-molecular-dynamics model in which the initial neutron and proton densities are sampled within the Skyrme–Hartree–Fock model, using which the neutron skin thickness (\(\Delta {R_{\rm{np}}}\)) is determined for different neutron-rich Ca isotopes. The results show that both R(n/p) and \(R(t/{^3}{\mathrm{He}})\) have strong linear correlations with \(\Delta {R_{\rm{np}}}\) of different Ca isotopic projectiles from five different centralities. It is suggested that R(n/p) and \(R(t/{^3}{\mathrm{He}})\), from the same centrality, could be treated as possible experimental observables to extract the neutron skin or halo thickness for neutron-rich isotopic nuclei, including the nuclei near the neutron drip line.
Keywords
Yield ratio Neutron skin thickness Isospin-dependent quantum-molecular-dynamicsReferences
- 1.J.M. Lattimer, M. Prakash, The physics of neutron stars. Science 304, 536 (2004). https://doi.org/10.1126/science.1090720 CrossRefGoogle Scholar
- 2.A.W. Steiner, M. Prakash, J.M. Lattimer et al., Isospin asymmetry in nuclei and neutron stars. Phys. Rep. 411, 325 (2005). https://doi.org/10.1016/j.physrep.2005.02.004 CrossRefGoogle Scholar
- 3.P. Russotto, M.D. Cozma, A.L. Févre et al., Flow probe of symmetry energy in relativistic heavy-ion reactions. Eur. Phys. J. A 50, 38 (2014). https://doi.org/10.1140/epja/i2014-14038-5 CrossRefGoogle Scholar
- 4.Z. Kohley, S.J. Yennello, Heavy-ion collisions: direct and indirect probes of the density and temperature dependence of \({E}_{{\rm sym}}\). Eur. Phys. J. A 50, 31 (2014). https://doi.org/10.1140/epja/i2014-14031-0 CrossRefGoogle Scholar
- 5.F. Gagnon-Moisan, E. Galichet, M.-F. Rivet et al., New isospin effects in central heavy-ion collisions at Fermi energies. Phys. Rev. C 86, 044617 (2012). https://doi.org/10.1103/PhysRevC.86.044617 CrossRefGoogle Scholar
- 6.F.F. Duan, X.Q. Liu, W.P. Lin et al., Investigation on symmetry and characteristic properties of the fragmenting source in heavy-ion reactions through reconstructed primary isotope yields. Nucl. Sci. Tech. 27, 131 (2016). https://doi.org/10.1007/s41365-016-0138-y CrossRefGoogle Scholar
- 7.B.A. Li, C.M. Ko, Z.Z. Ren, Equation of state of asymmetric nuclear matter and collisions of neutron-rich nuclei. Phys. Rev. Lett. 78, 1644 (1997). https://doi.org/10.1103/PhysRevLett.78.1644 CrossRefGoogle Scholar
- 8.J.Y. Liu, Q. Zhao, S.Q. Wang et al., Entrance channel dependence and isospin dependence of preequilibrium nucleon emission in intermediate energy heavy ion collisions. Nucl. Phys. A 687, 475 (2001). https://doi.org/10.1016/S0375-9474(00)00581-9 CrossRefGoogle Scholar
- 9.X.G. Cao, J.G. Chen, Y.G. Ma et al., Density effect of the neutron halo nucleus induced reactions in intermediate energy heavy ion collisions. Chin. Phys. C 33, 49–51 (2009). https://doi.org/10.1088/1674-1137/33/S1/016 CrossRefGoogle Scholar
- 10.L.W. Chen, C.M. Ko, B.A. Li, Effects of momentum-dependent nuclear potential on two-nucleon correlation functions and light cluster production in intermediate energy heavy-ion collisions. Phys. Rev. C 69, 054606 (2004). https://doi.org/10.1103/PhysRevC.69.054606 CrossRefGoogle Scholar
- 11.L. Shi, P. Danielewicz, Nuclear isospin diffusivity. Phys. Rev. C 68, 064604 (2003). https://doi.org/10.1103/PhysRevC.68.064604 CrossRefGoogle Scholar
- 12.H.S. Xu, M.B. Tsang, T.X. Liu et al., Nuclear isospin diffusivity. Phys. Rev. Lett. 85, 716 (2000). https://doi.org/10.1103/PhysRevLett.85.716 CrossRefGoogle Scholar
- 13.D.Q. Fang, Y.G. Ma, C. Zhong et al., Systematic study of isoscaling behavior in projectile fragmentation by the statistical abrasion–ablation model. J. Phys. G: Nucl. Part. Phys. 34, 2173 (2007). https://doi.org/10.1088/0954-3899/34/10/007 CrossRefGoogle Scholar
- 14.C.W. Ma, H.L. Wei, Y.G. Ma, Neutron-skin effects in isobaric yield ratios for mirror nuclei in a statistical abrasion–ablation model. Phys. Rev. C 88, 044612 (2013). https://doi.org/10.1103/PhysRevC.88.044612 CrossRefGoogle Scholar
- 15.B.A. Li, A.T. Sustich, B. Zhang, Proton differential elliptic flow and the isospin dependence of the nuclear equation of state. Phys. Rev. C 64, 054604 (2001). https://doi.org/10.1103/PhysRevC.64.054604 CrossRefGoogle Scholar
- 16.M.D. Cozma, Neutron–proton elliptic flow difference as a probe for the high density dependence of the symmetry energy. Phys. Lett. B 700, 139–144 (2011). https://doi.org/10.1016/j.physletb.2011.05.002 CrossRefGoogle Scholar
- 17.X.F. Li, D.Q. Fang, Y.G. Ma, Determination of the neutron skin thickness from interaction cross section and charge changing 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
- 18.X.G. Cao, X.Z. Cai, Y.G. Ma et al., Nucleon–nucleon momentum-correlation function as a probe of the density distribution of valence neutrons in neutron-rich nuclei. Phys. Rev. C 86, 044620 (2012). https://doi.org/10.1103/PhysRevC.86.044620 CrossRefGoogle Scholar
- 19.N. Wan, C. Chang, Z.Z. Ren, Exploring the sensitivity of \(\alpha\)-decay half-life to neutron skin thickness for nuclei around \({^{208}}{\text{Pb}}\). Nucl. Sci. Tech. 28, 22 (2017). https://doi.org/10.1007/s41365-016-0174-7 CrossRefGoogle Scholar
- 20.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
- 21.Z.T. Dai, D.Q. Fang, Y.G. Ma et al., \({\text{Triton}}/{^3}{\text{He}}\) ratio as an observable for neutron-skin thickness. Phys. Rev. C 89, 014613 (2014). https://doi.org/10.1103/PhysRevC.89.014613 CrossRefGoogle Scholar
- 22.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
- 23.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
- 24.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
- 25.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
- 26.W.B. He, X.G. Cao, Y.G. Ma et al., Application of EQMD model to researches of nuclear exotic structures. Nucl. Tech. 37, 100511 (2014). https://doi.org/10.11889/j.0253-3219.2014.hjs.37.100511. (in Chinese)CrossRefGoogle Scholar
- 27.L.W. Chen, C.M. Ko, B.A. Li, Light clusters production as a probe to nuclear symmetry energy. Phys. Rev. C 68, 017601 (2003). https://doi.org/10.1103/PhysRevC.68.017601 CrossRefGoogle Scholar
- 28.D. Theriault, J. Gauthier, F. Grenier et al., Neutron-to-proton ratios of quasiprojectile and midrapidity emission in the \(^{64}{\text{Zn}}+^{64}{\text{Zn}}\) reaction at 45 MeV/nucleon. Phys. Rev. C 74, 051602(R) (2006). https://doi.org/10.1103/PhysRevC.74.051602 CrossRefGoogle Scholar