1.7, where chemical freeze-out temperature becomes independent of collision energy. Similarly, the ratio $N_{ch}/N_{decays}$ also increase with $\sqrt{s_{NN}}$ and gets saturated at SPS energies around 0.6. Although, these findings are the same as observed in [@Cleymans:2007uk] but the difference occurs at lower energies where the excluded-volume correction is more effective.

![The variation of $N_{decays}/N$ (upper panel) and $N_{ch}/N_{decays}$ (lower panel) with $\sqrt{s_{NN}}$ at chemical freeze-out.](Nch_Ndecays.pdf){height="25em"}

In this paper, we want to study the variations of $E_{T}/N_{ch}$ with respect to centrality for various $\sqrt{s_{NN}}$. For this purpose, we connect centrality in terms of number of participants ($N_{part}$) with T and $\mu_{B}$ by studying the centrality dependence of particle ratios in our model. Figure 2 represents the variations of various hadron ratios such as $K^{+}/\pi^{+}$, $K^{-}/\pi^{-}$, $K^{-}/K^{+}$, and $\bar{p}/p$ with respect to number of participants, $N_{part}$ for Au-Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. In order to calculate $N_{part}$ dependence of ratios, we relate the freeze-out parameters T and $\mu_{B}$ with $N_{part}$ at this energy. We select three centrality bins with participant numbers 328$\pm$6 (most-central), 140$\pm$11 (mid-central), and 62$\pm$10 (peripheral) while calculating the particle ratios. We find that the freeze-out parameters T and $\mu_{B}$ do not vary much with $N_{part}$. Having done 