Impact parameter dependence of the disappearance of transverse flow in nuclear collisions

Abstract

The impact parameter dependence of the disappearance of directed transverse flow has been investigated for $^{40}\mathrm{Ar}$+$^{45}\mathrm{Sc}$ reactions using the Michigan State University $4\ensuremath{\pi}$ Array upgraded with the High Rate Array (HRA). The energy at which collective transverse flow in the reaction plane disappears, the balance energy (${E}_{\mathrm{bal}}$), is found to increase approximately linearly as a function of impact parameter. Comparison of our measured values of ${E}_{\mathrm{bal}}(b)$ shows agreement with predictions of Quantum Molecular Dynamics (QMD) model calculations.