Event-by-event analysis of baryon-strangeness correlations: Pinning down the critical temperature and volume of quark-gluon-plasma formation

Abstract

The recently proposed baryon-strangeness correlation (${C}_{\mathrm{BS}}$) is studied with a string-hadronic transport model (UrQMD) for various energies from ${E}_{\mathrm{lab}}=4A$ GeV to $\sqrt{s}=200A$ GeV. It is shown that rescattering among secondaries cannot mimic the predicted correlation pattern expected for a quark-gluon-plasma. However, we find a strong increase of the ${C}_{\mathrm{BS}}$ correlation function with decreasing collision energy for $p+p$ and Au+Au and/or Pb+Pb reactions. For Au+Au reactions at the top BNL Relativistic Heavy Ion Collider energy ($\sqrt{s}=200A$ GeV), the ${C}_{\mathrm{BS}}$ correlation is constant for all centralities and compatible with the $p+p$ result. With increasing width of the rapidity window, ${C}_{\mathrm{BS}}$ follows roughly the shape of the baryon rapidity distribution. We suggest studying the energy and centrality dependence of ${C}_{\mathrm{BS}}$ to gain information on the onset of the deconfinement transition in temperature and volume.