Chapter 6
On the Fragment Production and Phase
Transition Using QMD + SACA Model
S. Sood, Rohit Kumar, Arun Sharma, and Rajeev K. Puri
Abstract In the present study, we have shown the role of different clusterization
algorithms on the signals of liquid–gas phase transition in the multifragmentation for
the central reactions of
40 Ar +
45 Sc. We have used the quantum molecular dynamics (QMD) model to generate the phase space of the nucleons and clusterization
algorithms based on spatial constraints and its variants, and the energy-based clusterization algorithm. We also present the correlations among fragments within the
events via constructing correlation function. We find that the energy-based clusterization algorithm, i.e., simulated annealing clusterization algorithm (SACA) is the
most successful among all the available clusterization algorithms. We also find that
the event-by-event analysis unfolds and helps to understand reaction picture much
better than the quantities constructed by averaging over events.
6.1 Introduction
When the nucleus is excited to more than its binding energy, it decays into number of
small chunks known as fragments and the phenomenon is known as multifragmentation. Over the last few decades, an extensive experimental and theoretical efforts have
helped us to understand that the fragment number, fragment size (charge), and other
fragment properties depend crucially on various entrance channels such as incident
energy of projectile, mass of colliding nuclei, impact parameter of a reaction, and
isospin content of the colliding nuclei. [1–3].
The nucleon–nucleon interaction is constituted by two parts: long range attractive part and short-range repulsive part. Differing by five orders of magnitude, the
S. Sood · R. Kumar (B) · R. K. Puri
Department of Physics, Panjab University, Chandigarh 160014, India
e-mail: rohitksharma.pu@gmail.com
R. K. Puri
e-mail: drrkpuri@gmai.com
A. Sharma
Department of Physics, GDC Billawar, Jammu 185204, India
e-mail: arungaur.ju@gmail.com
© Springer Nature Singapore Pte Ltd. 2021
R. K. Puri et al. (eds.), Advances in Nuclear Physics, Springer Proceedings
in Physics 257, https://doi.org/10.1007/978-981-15-9062-7_6
65
On the Fragment Production and Phase
Transition Using QMD + SACA Model
S. Sood, Rohit Kumar, Arun Sharma, and Rajeev K. Puri
Abstract In the present study, we have shown the role of different clusterization
algorithms on the signals of liquid–gas phase transition in the multifragmentation for
the central reactions of
40 Ar +
45 Sc. We have used the quantum molecular dynamics (QMD) model to generate the phase space of the nucleons and clusterization
algorithms based on spatial constraints and its variants, and the energy-based clusterization algorithm. We also present the correlations among fragments within the
events via constructing correlation function. We find that the energy-based clusterization algorithm, i.e., simulated annealing clusterization algorithm (SACA) is the
most successful among all the available clusterization algorithms. We also find that
the event-by-event analysis unfolds and helps to understand reaction picture much
better than the quantities constructed by averaging over events.
6.1 Introduction
When the nucleus is excited to more than its binding energy, it decays into number of
small chunks known as fragments and the phenomenon is known as multifragmentation. Over the last few decades, an extensive experimental and theoretical efforts have
helped us to understand that the fragment number, fragment size (charge), and other
fragment properties depend crucially on various entrance channels such as incident
energy of projectile, mass of colliding nuclei, impact parameter of a reaction, and
isospin content of the colliding nuclei. [1–3].
The nucleon–nucleon interaction is constituted by two parts: long range attractive part and short-range repulsive part. Differing by five orders of magnitude, the
S. Sood · R. Kumar (B) · R. K. Puri
Department of Physics, Panjab University, Chandigarh 160014, India
e-mail: rohitksharma.pu@gmail.com
R. K. Puri
e-mail: drrkpuri@gmai.com
A. Sharma
Department of Physics, GDC Billawar, Jammu 185204, India
e-mail: arungaur.ju@gmail.com
© Springer Nature Singapore Pte Ltd. 2021
R. K. Puri et al. (eds.), Advances in Nuclear Physics, Springer Proceedings
in Physics 257, https://doi.org/10.1007/978-981-15-9062-7_6
65