Sanjeev Kumar

Publications (13) View all

• Source

  Available from: ArXiv

  Article: Rapidity distribution as a probe for elliptical flow at intermediate energies

  Sanjeev Kumar, Varinderjit Kaur, Suneel Kumar
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  ABSTRACT: Interplay between the spectator and participant matter in heavy-ion collisions is investigated within isospin dependent quantum molecular dynamics (IQMD) model in term of rapidity distribution of light charged particles. The effect of different types and size rapidity distributions is studied in elliptical flow. The elliptical flow patterns show important role of the nearby spectator matter on the participant zone. This role is further explained on the basis of passing time of the spectator and expansion time of the participant zone. The transition from the in-plane to out-of-plane is observed only when the mid-rapidity region is included in the rapidity bin, otherwise no transition occurs. The transition energy is found to be highly sensitive towards the size of the rapidity bin, while weakly on the type of the rapidity distribution. The theoretical results are also compared with the experimental findings and are found in good agreement.
  10/2010;
• Source

  Available from: arxiv.org

  Article: Energy of vanishing flow in heavy-ion collisions: Role of Coulomb interactions and asymmetry of a reaction

  Sanjeev Kumar, Varinderjit Kaur, Suneel Kumar
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  ABSTRACT: We aim to understand the role of Coulomb interactions as well as of different equations of state on the disappearance of transverse flow for various asymmetric reactions leading to same total mass. For the present study, the total mass of the system is kept constant (ATOT = 152) and asymmetry of the reaction is varied between 0.2 and 0.7. We find that the contribution of mean-field at low incident energies is more for nearly symmetric systems, while the trend is opposite at higher incident energies. The Coulomb interactions as well as different equations of state are found to affect the balance energy significantly for larger asymmetric reactions.
  09/2010;
• Source

  Available from: ArXiv

  Article: Sensitivity of elliptical flow in intermediate energy heavy-ion collisions

  Sanjeev Kumar, Rajeev Chugh
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  ABSTRACT: The detailed analysis of excitation function of elliptical flow by taking into account the nature of equation of state, nucleon-nucleon cross sections as well as momentum dependent interactions is performed within Quantum Molecular Dynamics (QMD)model. All the observables are found to sensitive towards the elliptical flow. The transition energy is found to be decrease with increase in the size of the fragment in the presence of static equation of state as well as with large cross sections, while, trend gets opposite when momentum dependent interactions are included. At last, the experimental data is verified with static hard equation of state in the presence of large cross sections.
  09/2010;
• Source

  Available from: ArXiv

  Article: Rapidity distribution dependence of the transition energy in heavy-ion collisions

  Sanjeev Kumar, Suneel Kumar
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  ABSTRACT: For the present analysis, simulations are carried out for thousand of events for the reaction of 79Au197 + 79Au197 at semi-central geometry using a hard equation of state. The whole of the analysis is performed for light charged particles (LCP's). The transition from in-plane to out-of-plane is observed only when the mid-rapidity region is included in the rapidity bin otherwise no transition is observed. The transition energy is found to be strongly dependent on the size of the rapidity bin. The transition energy is parameterized with a straight line interpolation.
  09/2010;
• Source

  Available from: arxiv.org

  Article: Study of gold induced heavy ion collisions using isospin dependent QMD model

  Bhawna Sharma, Sanjeev Kumar, Suneel Kumar, Rajeev K. Puri
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  ABSTRACT: We have studied the fragment production mechanism in the set of four reactions 197Au79+12C6, 197Au79+26Al13, 197Au79+63Cu29 and 197Au79+208Pb82. The reactions are simulated at an energy 600 MeV/nucleon and collision geometry is varied from central to peripheral (= b/bmax = 0 to 1). A theoretical investigation has been carried out on the study of mass dependence of intermediate mass fragments (5\leqA\leqAtot/6) and other fragments. It is observed that multiplicity shows a good agreement for low Zbound, but it fails for high Zbound. This failure is due the method of analysis MST which we had used in our analysis, because MST method gives one heavy cluster at the time of high density. The discrepancy between theory and experiments can be removed by using reduced isospin dependent NN cross section and sophisticated clustrization algorithm SACA.
  09/2010;