Onset of pressure gradient on collective flow through balance and transition geometry

The impression of mean field and spectator matter has been studied through the collision geometry dependence reduced flow elliptical in heavy-ion collisions (HICs) at intermediate energies using Isospindependent Quantum Molecular Dynamics (IQMD) model for reaction $$_{20}^{50}{\rm{Cu + }}_{20}^{50}{\rm{and}}_{79}^{197}{\rm{Au }}_{79}^{197}{\rm{Au}}$$ incident energy between 50 MeV/nucleon 450 MeV/nucleon. which changes its sign is termed as balance $$({\hat b_{bal}})$$ transition b_{trans}})$$ flow, respectively. Our study reveals that increases with increase energy. In addition to this, effect nuclear charge radius also by isospin-independent well dependent radii parameterizations.