Sakshi Gautam

Isospin effects on the energy of vanishing flow in heavy-ion collisions

Using the isospin-dependent quantum molecular dynamics model we study the isospin effects on the disappearance of flow for the reactions of 58Ni + 58Ni and 58Fe + 58Fe as a function of the impact parameter. We found good agreement between our calculations and experimentally measured energy of vanishing flow at all colliding geometries. Our calculations reproduce the experimental data within 5% (10%) at central (peripheral) geometries.

Sensitivity of the transverse flow to the symmetry energy

We study the sensitivity of transverse flow to symmetry energy in the Fermi energy region as well as at high energies. We find that transverse flow is sensitive to symmetry energy and its density dependence in the Fermi energy region. We also show that the transverse flow can address the symmetry energy at densities about twice the saturation density; however, it shows insensitivity to the symmetry energy at densities {rho}/{rho}{sub 0}>2. The mechanism for the sensitivity of transverse flow to symmetry energy and its density dependence is also discussed.

Isospin effects in the disappearance of flow as a function of colliding geometry

We study the effect of isospin degree of freedom on the balance energy (E{sub bal}) as well as its mass dependence throughout the mass range 48-270 for two sets of isobaric systems with N/Z=1 and 1.4 at different colliding geometries ranging from central to peripheral ones. Our findings reveal the dominance of Coulomb repulsion in isospin effects on E{sub bal} as well as its mass dependence throughout the range of the colliding geometry. Our results also indicate that the effect of symmetry energy and nucleon-nucleon cross section on E{sub bal} is uniform throughout the mass range and throughout the colliding geometry. We also present the counterbalancing of nucleon-nucleon collisions and mean field by reducing the Coulomb and the counterbalancing of Coulomb and mean field by removing the nucleon-nucleon collisions.

Sensitivity of transverse flow toward isospin-dependent cross sections and symmetry energy

We study the transverse flow for systems having various N/Z ratios. We find the transverse flow is sensitive to N/Z ratio and, in fact, increases with N/Z of the system. The relative contribution of symmetry energy and isospin dependence of nucleon-nucleon cross section is also investigated. We find the greater sensitivity of symmetry energy in the lighter systems compared to heavier ones.

Isospin effects on the mass dependence of the balance energy

We study the effect of isospin degree of freedom on balance energy throughout the mass range between 50 and 350 for two sets of isotopic systems with N/A= 0.54 and 0.57 as well as isobaric systems with N/A= 0.5 and 0.58. Our findings indicate that different values of balance energy for two isobaric systems may be mainly due to the Coulomb repulsion. We also demonstrate clearly the dominance of Coulomb repulsion over symmetry energy.

Participant-spectator matter and thermalization of neutron-rich systems at the energy of vanishing flow

We study the participant-spectator matter at the energy of vanishing flow for neutron-rich systems. Our study reveals similar behaviour of articipant-spectator for neutron-rich systems as for stable systems and also points towards nearly mass independence behaviour of participant-spectator matter for neutron-rich systems at the energy of vanishing flow. We also study the thermalization reached in the reactions of neutron-rich systems.

Density and temperature of neutron-rich systems at the energy of vanishing flow in heavy-ion collisions

We study nuclear dynamics at the the energy of vanishing flow for neutron-rich systems. In particular, we study the collision rate, density, and temperature reached in a heavy-ion reaction with neutron-rich systems and the mass dependence of these quantities. Our results indicate nearly mass-independent nature for the density, whereas a significant mass dependence exists for the temperature of neutron-rich systems.

Influence of different binding energies in clusterization approach: fragmentation as an example

We study multifragmentation within the framework of a quantum molecular dynamics model using different binding energy formulae in the secondary algorithm; namely, the minimum spanning tree approach. A comparison of theoretical results with experimental data over a wide range of energy, mass and impact parameter is also presented. Our detailed analysis shows an insignificant difference of different binding energies when used at finite temperatures on the fragmentation pattern which, on the other hand, becomes significant when used for cold matter.

On the isospin effects in the geometry of vanishing flow in heavy-ion collisions

We study the behavior of the geometry of vanishing flow (GVF) and its system size dependence at different incident energies. We find that the geometry of vanishing flow is sensitive to the incident energy. We also study the role of isospin degree of freedom through Coulomb potential, symmetry energy and nucleon-nucleon cross sections. Our study reveals that isospin degree of freedom through nucleon-nucleon cross section plays a dominant role compared to Coulomb potential and symmetry energy.

Fragmentation and momentum correlations in heavy-ion collisions

The role of momentum correlations in the production of light and medium mass fragments is studied by imposing momentum cut in the clusterization of the phase space. Our detailed investigation shows that momentum cut has a major role to play in the emission of fragments. A comparison with the experimental data is also presented. The calculations showed better agreement with the experimental data when momentum cut is imposed.