Predictions for squeezed back-to-back correlations of $\phi\phi$ and $K^+K^-$ in high-energy heavy-ion collisions by event-by-event hydrodynamics

TL;DR

This paper predicts the behavior of squeezed back-to-back correlations of specific meson pairs in high-energy heavy-ion collisions using event-by-event hydrodynamics, suggesting potential observability in certain collision conditions.

Contribution

It introduces a detailed calculation of BBC functions for $\,\,\phi\phi$ and $K^+K^-$ pairs using fluctuating initial conditions in hydrodynamics, highlighting differences across collision energies and systems.

Findings

BBC functions are larger at RHIC energies than at LHC energies.

Potential observation of $\,\phi\phi$ BBC in peripheral collisions.

Smaller sources like Cu+Cu show larger BBC signals.

Abstract

We calculate the squeezed back-to-back correlation (BBC) functions of $\phi \phi$ and $K^+K^-$ for heavy-ion collisions at RHIC and LHC energies, using ($2+1$)-dimensional hydrodynamics with fluctuating initial conditions. The BBC functions averaged over event-by-event calculations for many events for the hydrodynamic sources are smoothed as a function of the particle momentum. For heavy-ion collisions of Au+Au at $\sqrt{s_{NN}}=200$ GeV, the BBC functions are larger than those for collisions of Pb+Pb at $\sqrt{s_{NN}}=2.76$ TeV. The BBC of $\phi\phi$ may possibly be observed in peripheral collisions at the RHIC and LHC energies. It is large for the smaller sources of Cu+Cu collisions at $\sqrt{s_{NN}}=200$ GeV.