An almost-entirely precise empirical estimation for various chemical potentials

Abstract

The transverse momentum spectra of the well-identified produced particles, $\pi^+$, $\pi^-$, $K^+$, $K^-$, $p$, $\bar{p}$, $K_s^0$, $\Lambda$, $\bar{\Lambda}$, $\Xi^-$, and $\Xi^+$ are analyzed in a statistical approach. From the partition function of grand-canonical ensemble, we propose a generic expression for the dependence of the generic chemical potential $\mu$ on the rapidity $y$. Then, by fitting this expression to the experimental results on the most central $p_{\perp}$ and $d^2 N/2 \pi p_{\bot} dp_{\bot} dy$, at energies ranging from $7.7$ to $200~$GeV, we have introduced a generic expression for the rapidity dependence of $\mu$, at different energies, namely $\mu=a+b y^2$, where $a$ and $b$ is constants. We find that the resulting energy dependence $\sqrt{s_{\mathtt{NN}}}=c[(\mu-a)/b]^{d/2}$ agrees well with the statistical thermal models. We also present precise estimations of various types of chemical potentials, $\mu_B$, $\mu_S$, and $\mu_Q$, the baryon, the strangeness, and the charge chemical potential, respectively.