with flow explains the data satisfactorily. After comparison with the experimental data, we get the value of the $\beta_s$, from which we calculate the average radial flow velocity. Here, our model with flow explains the experimental data successfully except at lower $p_{T}$, where the contribution of resonance decay plays an important role [@Chatterjee:2015fua]. In this paper, we do not take the contributions of resonance decays while calculating $p_T$ spectra and we reserve this for a future work.

![The variations of the radial flow velocity ($\langle\beta_r\rangle$) extracted in our model with respect to $\sqrt{s_{NN}}$. The solid line is a power-law fit as mentioned in the text.](flow1.pdf){height="25em"}

Figure 8 shows the variations of average radial flow velocity, $\langle\beta_r\rangle$ extracted in the framework of EV-SHGM with respect to $\sqrt{s_{NN}}$ from lower AGS energies to LHC energies. We notice that it increases monotonically with the collision energy with it’s lowest value at AGS to the highest value at LHC. This shows significant collectivity in high energy heavy-ion collisions. We fit a phenomenologically motivated power-law function, [*i. e.*]{} $\displaystyle a + b(\sqrt{s_{NN}})^{c}$ to the energy dependence of $\langle\beta_r\rangle$. Here, a, b and c are the fit parameters. For the best fit we get, a = 