Abstract
Quantum molecular dynamics (QMD) is used to investigate multifragmentation resulting from an expanding nuclear matter. Equation of state, the structure of nuclear matter and symmetric nu-clear matter is discussed. Also, the dependence of the fragment mass distribution on the initial temperature (Tinit) and the radial flow velocity (h) is studied. When h is large, the distribution shows exponential shape, whereas for small h, it obeys the exponentially falling distribution with mass number. The cluster formation in an expanding system is found to be different from the one in a thermally equilibrated system. The used Hamiltonian has a classical kinetic energy term and an effective potential term composed of four parts.
Highlights
Multifragmentation has been a long-standing topic in nuclear physics
A fragment mass distribution has been extensively investigated both theoretically and experimentally as a phenomenon which might have some connection with nuclear phase transition [1,2,3,4,5,6]
This exponentially falling distribution with mass number behavior has attracted many authors’ interest because the exponentially falling distribution with mass number is a signature of a second order phase transition [8,9,10,11,12,13]
Summary
Multifragmentation has been a long-standing topic in nuclear physics. In particular, a fragment mass distribution has been extensively investigated both theoretically and experimentally as a phenomenon which might have some connection with nuclear phase transition [1,2,3,4,5,6]. We cannot regard this source of fragments as thermal equilibrated object that the statistical model assumes In this region, the mass distribution does not obey the power law but obeys an exponential distribution and the shape of which strongly depends on the collision energy [5,6]. In this study we simulate an infinite system by the periodic boundary condition mainly with 1024 or 2048 particles in a cell, and investigate the ground state properties of nuclear matter. The ‘‘uniform’’ matter energy is calculated as follows: First we distribute nucleons randomly and cool the system only with the Pauli potential. Note that simulated ‘‘uniform’’ matter is not exactly the same as ideal nuclear matter since the latter is continuous and completely uniform Both cases of uniform and energy-minimum configurations have almost the same energy per nucleon for the higher densities as is seen in this figure.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
