Disappearance of flow in heavy-ion collisions

Initialization effects via the nuclear radius on transverse in-plane flow and its disappearance

“…The balance energy (representing the vanishing of flow) is of great significance because the experimentally determined balance energy can be easily compared with various theoretical calculations as it is free from any experimental uncertainties. Detailed theoretical studies using various transport models have revealed its sensitivity to the EOS and the in-medium nucleon-nucleon crosssection as well as to various entrance channel parameters [6,[8][9][10][11][12]. At the same time, the collective transverse flow and its disappearance has also been found to depend on the isospin degree of freedom [13,14].…”

“…The collective transverse flow is directly connected to the dynamic evolution of the reaction, and is sensitive to the momentum dependence of the mean field [2,3], the nucleon-nucleon cross-section [4], different equations of state (EOS) [5] and as well as to various reaction parameters such as the incident energy [6], colliding geometry [7] and mass of the colliding system [3,7,8]. The beam energy dependence of the collective transverse flow leads to its disappearance at a particular energy termed the balance energy [9]. The balance energy is the result of the counterbalancing of the attractive mean field (which is dominant at low incident energies) and the repulsive nucleon-nucleon scattering, which decides the fate of the reaction at higher incident energies.…”

Progress in Collective Flow Studies from the Onset to Bevalac/SIS

“…Flow disappears at the so-called balance energy, Ebal, where these two effects cancel each other. The disappearance of flow was first observed in the La+La system [29], and has since been measured for a large number of target-projectile combinations from C+C [30] to (a lower limit for) Au+Au [31].…”

Role of model ingredients on the directed flow and its disappearance using isospin dependent quantum molecular dynamics model

“…The dependence of transverse flow to various entrance channel parameters like incident energy [4], system size [2], colliding geometry [5,6], mass asymmetry [7] and isospin of the reacting nuclei [5,8] is well established experimentally as well as theoretically. The energy dependence of transverse flow, in particular is of great importance and it leads to a term known as balance energy (E bal ) or energy of vanishing flow (EVF), where attractive and repulsive interaction counterbalance each other [9]. The balance energy is of great significance because experimentally determined balance energy can be easily compared with various theoretical calculations as it is free from any experimental uncertainties.…”