Probing quark charge correlations by identified hadrons in ultrarelativistic $AA$ collisions

We propose a new kind of two-particle correlation of identified hadrons in longitudinal rapidity space which can reflect directly the conserved charge correlations of a hot quark system produced in $AA$ collisions at Large Hadron Collider (LHC) energies. It is derived from the basic scenario of quark combination mechanism of hadron production. Like the elliptic flow of identified hadrons at intermediate transverse momentum, this correlation is independent of the absolute hadronic yields but depends only on the flavor compositions of hadrons and thus exhibits interesting properties for different kinds of hadrons. We suggest the measurement of this correlation function in $AA$ collisions at the LHC to gain more insight into the charge-correlation properties of the produced hot quark matter.

Figure 1

$G_{p\overline{\mathrm{\Lambda }}}\left(\mathrm{\Delta }y\right),G_{p{\overline{\mathrm{\Xi }}}^0}\left(\mathrm{\Delta }y\right)$, and $G_{p{\overline{\mathrm{\Omega }}}^{+}}\left(\mathrm{\Delta }y\right)$ as a function of $\mathrm{\Delta }y$, as ${\chi }_{ab}$ matrix is diagonal (filled circles), has positive off-diagonal elements (open squares) and has negative off-diagonal elements (open circles).

Figure 2

$G_{\alpha \beta }\left(\mathrm{\Delta }y\right)$ of initial hadrons produced at hadronization (open circles) and those including strong and electromagnetic decays (open squares), as the quark system existed previously has vanishing off-diagonal correlation-matrix elements.