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Supriya Goyal

Publications and source records attributed to Supriya Goyal.

At least 19 recordsLinked to original sources
arXiv2011

On the stability of nuclei in semi-classical quantum molecular dynamics model

The stability of nuclei is discussed with respect to the width of the Gaussian wave packets within Quantum Molecular Dynamics model. A detailed study is carried out by taking different equations of state (i.e., static soft and hard and the momentum dependent soft and hard) for the selected nuclei from 12C to 197Au. A comparison is done by using standard and broader Gaussian wave packets. We find that the nuclei propagating with broader Gaussian wave packets remain stable for entire reaction time span.

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arXiv2011

Nuclear dynamics at the balance energy of mass asymmetric colliding nuclei

Using the quantum molecular dynamics model, we study the nuclear dynamics at the balance energy of mass asymmetric colliding nuclei by keeping the total mass of the system fixed as 40, 80, 160, and 240. The calculations are performed by varying the mass asymmetry ($η$ = $\frac{A_{T}-A_{P}}{A_{T}+A_{P}}$; where $A_{T}$ and $A_{P}$ are the masses of the target and projectile, respectively) of the reaction from 0.1 to 0.7. In particular, we study the various quantities like average and maximum density, collision rate, participant-spectator matter, anisotropic ratio, relative momentum as well as their mass asymmetry and mass dependence. We find sizeable effects of mass asymmetry on these quantities. Our results indicate that the mass dependence of various quantities increases slightly with increase in $η$.

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arXiv2011

Multifragmentation at the balance energy of mass asymmetric colliding nuclei

Using the quantum molecular dynamics model, we study the role of mass asymmetry of colliding nuclei on the fragmentation at the balance energy and on its mass dependence. The study is done by keeping the total mass of the system fixed as 40, 80, 160, and 240 and by varying the mass asymmetry of the ($η$ = $\frac{A_{T}-A_{P}}{A_{T}+A_{P}}$; where $A_{T}$ and $A_{P}$ are the masses of the target and projectile, respectively) reaction from 0.1 to 0.7. Our results clearly indicate a sizeable effect of the mass asymmetry on the multiplicity of various fragments. The mass asymmetry dependence of various fragments is found to increase with increase in total system mass (except for heavy mass fragments). Similar to symmetric reactions, a power law system mass dependence of various fragment multiplicities is also found to exit for large asymmetries.

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arXiv2011

Impact parameter dependence of collective flow and its disappearance for different mass asymmetries

We study the role of impact parameter on the collective flow and its disappearance for different mass asymmetric reactions. The mass asymmetry is varied from 0 to 0.7 keeping the total mass of the system fixed. Our results clearly indicate a significant role of impact parameter on the collective flow and its disappearance for the mass asymmetric reactions. The impact parameter dependence is also found to vary with mass asymmetry of the reaction.

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arXiv2011

Systematic study of multifragmentation in Au-Au collisions

We performed a systematic study of the formation of fragments with different mass ranges in 197Au+197Au collisions at incident energies between 20 - 1000 MeV/nucleon and at impact para- meter between ^b = 0-0.98. The aim of present study is to understand the complex dependence of fragment production on incident energy and impact parameter. Our results clearly indicate that the QMD simulations of 197Au+197Au predict different behavior for different mass ranges than for IMF's with a change in incident energy and impact parameter. All charge yields can be parameterized by a power law and no signal of liquid-gas phase transition is seen as no unique dependence of tau on impact parameter is seen.

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arXiv2011

Formation of fragments in heavy-ion collisions using modified clusterization method

We study the formation of fragments by extending the minimum spanning tree method (MST) for clusterization. In this extension, each fragment is subjected to a binding-energy check calculated using the modified Bethe-Weizsacker formula. Earlier, a constant binding-energy cut of 4 MeV/nucleon was imposed. Our results for 197Au +197 Au collisions are compared with ALADiN data and also with the calculations based on the simulated annealing technique. We shall show that the present modified version improves the agreement compared to the MST method.

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arXiv2011

On the sensitivity of the energy of vanishing flow towards mass asymmetry of colliding nuclei

We demonstrate the role of the mass asymmetry in the energy of vanishing flow by studying asymmetric reactions throughout the periodic table and over entire colliding geometry. Our results, which are almost independent of the system size and as well as of the colliding geometries indicate a sizable effect of the asymmetry of the reaction on the energy of vanishing flow.

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arXiv2011

Role of the mass asymmetry of reaction on the geometry of vanishing flow

We study the transverse flow throughout the mass asymmetry range as a function of the impact parameter, keeping the total mass of the system fixed.We find that the geometry of vanishing flow (GVF) i.e. the impact parameter at which flow vanishes and its mass dependence is quite sensitive to the mass asymmetry of the reaction. With increase in the mass asymmetry, the value of GVF decreases, while its mass dependence increases. Our results indicate the sizable role of mass asymmetry on GVF as on balance energy.

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arXiv2011

Role of colliding geometry on the balance energy of mass-asymmetric systems

We study the role of colliding geometry on the balance energy (Ebal) of mass-asymmetric systems by varying the mass asymmetry (η = AT - Ap/AT + AP, where AT and AP are the masses of the target and projectile, respectively) from 0.1 to 0.7, over the mass range 40-240 and on the mass dependence of the balance energy. Our findings reveal that colliding geometry has a significant effect on the Ebal of asymmetric systems. We find that, as we go from central collisions to peripheral ones, the effect of mass asymmetry on Ebal increases throughout the mass range. Interestingly, we find that for every fixed system mass (Atot) the effect of the impact parameter variation is almost uniform throughout the mass-asymmetry range. For each η, Ebal follows a power-law behavior (\propto Aτ) at all colliding geometries

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arXiv2011

Influence of system mass on the emission of intermediate mass fragments

In the present study, we have simulated the central reactions of nearly symmetric and asymmetric systems over the entire periodic table for different values of energies using QMD model as event generator. These reactions are simulated for the different equations of state, nn cross-sections and different widths of Gaussians. We have observed that the multiplicity of IMFs shows a rise and fall with increase in beam energy in the center-of-mass frame as already predicted experimentally/theoretically. We have also studied the mass dependence of peak Ec.m. and peak . It has been observed that peak Ec.m. increases linearly with system mass whereas a power law dependence has been observed for peak IMFs with tau \approx 1.0. Our calculations using hard EoS along with cugnon cross-section and MSTB method are in good agreement with experimental data. Similar power law dependence is also observed for various fragments.

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arXiv2011

On the energy of vanishing flow for colliding nuclei leading to same compound nucleus

Our present studies has shown that the mass dependence of EVF show mass asymmetry independent behaviour. This is due the fact that with increase in asymmetry, the number of nucleon-nucleon collisions and repulsive Coulomb interactions decreases, therefore EVF increases. The increase in EVF with asymmetry is more for lighter nuclei as compared to heavier nuclei due to the further less magnitude of Coulomb repulsions in lighter nuclei as compared to heavier ones.

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