Probing multistrange dibaryons with proton-omega correlations in high-energy heavy ion collisions

The two-particle momentum correlation between the proton $\left(p\right)$ and the omega baryon $\left(\mathrm{\Omega }\right)$ in high-energy heavy ion collisions is studied to unravel the possible spin-2 $p\mathrm{\Omega }$ dibaryon recently suggested by lattice QCD simulations. The ratio of correlation functions between small and large collision systems, $C_{\mathrm{SL}}\left(Q\right)$, is proposed to be a new measure to extract the strong $p\mathrm{\Omega }$ interaction without much contamination from the Coulomb attraction. Relevance of this quantity to the experimental observables in heavy ion collisions is also discussed.

Figure 1

Three typical examples of the $N\mathrm{\Omega }$ potential. The black circles with error bars stand for the lattice QCD data with heavy quark masses [7]. $V_{\mathrm{II}}$ corresponds to a fit to the lattice data with a Gaussian + (Yukawa)${}^2$ form. $V_{\mathrm{II}}$ and $V_{\mathrm{III}}$ denote the potentials with weaker and stronger attractions, respectively. The Coulomb potential for the $p\mathrm{\Omega }$ system is also shown.

Figure 2

$p\mathrm{\Omega }$ correlation function for the static source with $R_p=R_{\mathrm{\Omega }}=2.5$ fm. The Coulomb interaction is switched off. (a) Solid (dashed) lines denote the correlations with only the ${}^{5}S_2$ scattering (with both the ${}^{5}S_2$ scattering and the ${}^{3}S_1$ absorption). (b) $C\left(Q\right)$ for $Q=20$, 40, and 60 MeV as a function of $a_0^{-1}$ obtained by changing the attraction of the $N\mathrm{\Omega }$ potential through the parameter $b_5$.

Figure 3

(a) Correlation function with both strong and the Coulomb attractions for two different values of the static source sizes, $R_{p,\mathrm{\Omega }}=2.5$ fm (solid lines) and 5 fm (dashed lines). (b) Same correlation function as (a), but divided by the Gamow factor.

Figure 4

$C_{\mathrm{SL}}\left(Q\right)$ for the static source between the different source sizes, $R_{p,\mathrm{\Omega }}=2.5$ and 5 fm.

Figure 5

$C_{\mathrm{SL}}\left(Q\right)$ as a function of (a) $Q$ for the three typical potentials and (b) $a_0^{-1}$. In both figures, both the strong and Coulomb interactions are included.