118298053
Role of Isospin Degree of freedom on the impact parameter dependence of balance energy
For this study we have simulated the 28Ni58+28Ni58 and 26Fe58+26Fe58 systems at incident energies ranging from 45 MeV/nucleon to 105 MeV/nucleon by using soft equation of state. The geometry of reactions chosen are = b/bmax = 0.2, 0.4, 0.5, 0.6, and 0.7.The Px/A is becoming more positive for neutron - rich system 26Fi58 as compared to neutron-poor system 28Ni58. This point towards the higher value of balance energy for 26Fi58 system. Further study in this direction is ongoing.
116542469
Study of gold induced heavy ion collisions using isospin dependent QMD model
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.
118085314
Rapidity distribution dependence of the transition energy in heavy-ion collisions
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.
119294715
Experimental balance energies and isospin-dependent nucleon-nucleon cross-sections
The effect of different isospin-dependent cross-sections on directed flow is studied for a variety of systems (for which experimental balance energies are available) using an isospin-dependent quantum molecular dynamic (IQMD) model. We show that balance energies are sensitive toward isospin-dependent cross sections for light systems, while nearly no effect exists for heavier nuclei. A reduced cross-section σ = 0.9σ NN with stiff equation of state is able to explain experimental balance energies in most of systems. A power law behavior is also given for the mass dependence of balance energy, which also follows the N/Z dependence.
118862615
Systematic Study on System Size Dependence of Global Stopping: Role of Momentum-Dependent Interactions and Symmetry Energy
Using the isospin-dependent quantum molecular dynamical (IQMD) model, we systematically study the role of momentum dependent interactions in global stopping and analyze the effect of symmetry energy in the presence of momentum dependent interactions. For this, we simulate the reactions by varying the total mass of the system from 80 to 394 at different beam energies from 30 to 1000 MeV/nucleon over central and semi-central geometries. The study is carried in the presence of momentum dependent interactions and symmetry energy by taking into account hard equation of state. The nuclear stopping is found to be sensitive towards the momentum dependent interactions and symmetry energy at low incident energies. The momentum dependent interactions are found to weaken the finite size effects in nuclear stopping.
119234278
Rapidity distribution as a probe for elliptical flow at intermediate energies
The interplay between spectator and participant matter in heavy-ion collisions is investigated within the isospin-dependent quantum molecular dynamics (IQMD) model in terms of the rapidity distribution of light charged particles. The effect of different types and sizes of rapidity distributions is studied in elliptical flow. The elliptical-flow patterns show the important role of nearby spectator matter on the participant zone. This role is further explained on the basis of the passing time of the spectator and the expansion time of the participant zone. The transition from in-plane to out-of-plane emission is observed only when the mid-rapidity region is included into the rapidity bin. Otherwise no transition occurs. The transition energy is found to be highly sensitive to the size of the rapidity bin, while it is only weakly dependent on the type of the rapidity distribution. These theoretical findings are found to be in agreement with experimental results.
100150271
Effect of density dependent symmetry energy on fragmentation
The effect of the density dependence of symmetry energy on fragmentation is studied using isospin-dependent quantum molecular dynamics model(IQMD) Model. We have used the reduced isospin-dependent cross-section with soft equation of state to explain the experimental findings for the system 79Au197 + 79Au197 for the full colliding geometry. In addition to that we have tried to study the collective response of the momentum dependent interactions(MDI) and symmetry energy towards the multifragmentation.
17544914
Precision test of AdS/CFT in Lunin-Maldacena background
We obtain the solutions and explicitly calculate the energy for a class of two-spin semiclassical string states in the Lunin-Maldacena background. These configurations are the β-deformed versions of the folded string solutions in AdS5 × S5 background. They correspond to certain single trace operators in the = 1 superconformal β deformation of = 4 Yang-Mills. We calculate the one loop anomalous dimension for the dual single trace operators from the associated twisted spin chain with a general two-cut distribution of Bethe roots. Our results show a striking match between the two calculations. We demonstrate the natural identification of parameters on the two sides of the analysis, and explain the significance of the Virasoro constraint associated with the winding motion of semiclassical strings from the perspective of the spin chain solution.
117351051
Influence of density dependence of symmetry energy on fragmentation
The fragmentation of projectile and spectator is studied at the different incident energies using isospin dependent QMD model with reduced isospin dependent cross-section. Different systems have been used for the analysis of fragment production(IMF). We have used enhanced constant isospin dependent cross-section to explain the experimental findings which is valid for soft equation of state. In addition to that we have tried to study the influence of density dependent symmetry energy on fragment production.
118551278
Theoretical Studies of Rare-Earth Nuclei leading to $_{50}$Sn-Daughter Products and the Associated Shell Effects
Cluster decays of rare-earth nuclei are studied with a view to look for neutron magic shells for the $_{50}$Sn nucleus as the daughter product always. The $^{100}$Sn and $^{132}$Sn radioactivities are studied to find the most probable cluster decays and the possibility, if any, of new neutron shells. For a wide range of parent nuclei considered here (from Ba to Pt) $^{12}$C from $^{112}$Ba and $^{78}$Ni from $^{210}$Pt parent are predicted to be the most probable clusters (minimum decay half-life) referring to $^{100}$Sn and $^{132}$Sn daughters, respectively. Also, $^{22}$Mg decay of $^{122}$Sm is indicated at the second best possibilty for $^{100}$Sn-daughter decay. In addition to these well known magic shells (Z=50, N=50 and 82), a new magic shell at Z=50, N=66 ($^{116}$Sn daughter) is indicated for the $^{64}$Ni decay from $^{180}$Pt parent.
59440238
Vacuum structure and flavor symmetry breaking in supersymmetric SO(nc) gauge theories
We determine the vacuum structure and phases of N=1 theories obtained via a 
mass \mu for the adjoint chiral superfield in N=2, SO(n_c) SQCD. For large 
number of flavors these theories have two groups of vacua. The first exhibits 
dynamical breaking of flavor symmetry \USp(2n_f) \to U(n_f) and arises as a 
relevant deformation of a non-trivial superconformal theory. These are in the 
confined phase. The second group, in an IR-free phase with unbroken flavor 
symmetry, is produced from a Coulomb branch singularity with Seiberg's dual 
gauge symmetry. In the large-\mu regime both groups of vacua are well-described 
by dual quarks and mesons, and dynamical symmetry breaking in the first group 
occurs via meson condensation. We follow the description of these vacua from 
weak to strong coupling and demonstrate a nontrivial agreement between the 
phases and the number of vacua in the two regimes. We construct the 
semiclassical monopole flavor multiplets and argue that their multiplicity is 
consistent with the number of N=1 vacua.