We study the sensitivity of transverse flow towards the different density dependence of symmetry energy in Fermi energy region. Our results show that transverse flow shows sensitivity to different density dependence of symmetry energy. The mechanism for sensitivity towards different density dependence of symmetry energy is also discussed.
The reactions of nucleon and polarized deuteron scattered off a heavy target at large impact parameter with intermediate energies have been investigated by using the improved quantum molecular dynamics model. It is found that, due to the difference e
ffect of isovector potential on proton and neutron, there is a significant difference between the angle distribution of elastic scattering protons and neutrons. To overcome the lack of monochromatic neutron beam, the reaction of polarized deuteron peripherally scattered off the heavy target is used to replace the reaction of individual proton and neutron scattered off heavy target to study the isospin effect. It is found that the distributions of elastic scattering angle of proton and neutron originating from the breakup of deuteron are very similar to the results of the individual proton- and neutron-induced reaction. A new probe more effective and more clean, namely the difference between elastic scattering angle of proton and neutron originating from the breakup of polarized deuteron, is promoted to constrain the symmetry energy at subsaturation density.
The relative isobaric yields of fragments produced in a series of heavy ion induced multifragmentation reactions have been analyzed in the framework of a Modified Fisher Model, primarily to determine the ratio of the symmetry energy coefficient to th
e temperature, $a_a/T$, as a function of fragment mass A. The extracted values increase from 5 to ~16 as A increases from 9 to 37. These values have been compared to the results of calculations using the Antisymmetrized Molecular Dynamics (AMD) model together with the statistical decay code Gemini. The calculated ratios are in good agreement with those extracted from the experiment. In contrast, the ratios determined from fitting the primary fragment distributions from the AMD model calculation are ~ 4 and show little variation with A. This observation indicates that the value of the symmetry energy coefficient derived from final fragment observables may be significantly different than the actual value at the time of fragment formation. The experimentally observed pairing effect is also studied within the same simulations. The Coulomb coefficient is also discussed.
We examine critically how tightly the density dependence of nuclear symmetry energy esym is constrained by the universal equation of state (EOS) of the unitary Fermi gas $E_{rm{UG}}(rho)$ considering currently known uncertainties of higher order para
meters describing the density dependence of the Equation of State of isospin-asymmetric nuclear matter. We found that $E_{rm{UG}}(rho)$ does provide a useful lower boundary for the esym. However, it does not tightly constrain the correlation between the magnitude $E_{rm{sym}}(rho_0)$ and slope $L$ unless the curvature $K_{rm{sym}}$ of the symmetry energy at saturation density $rho_0$ is more precisely known. The large uncertainty in the skewness parameters affects the $E_{rm{sym}}(rho_0)$ versus $L$ correlation by the same almost as significantly as the uncertainty in $K_{rm{sym}}$.
The nuclear symmetry energy represents a response to the neutron-proton asymmetry. In this survey we discuss various aspects of symmetry energy in the framework of nuclear density functional theory, considering both non-relativistic and relativistic
self-consistent mean-field realizations side-by-side. Key observables pertaining to bulk nucleonic matter and finite nuclei are reviewed. Constraints on the symmetry energy and correlations between observables and symmetry-energy parameters, using statistical covariance analysis, are investigated. Perspectives for future work are outlined in the context of ongoing experimental efforts.