Squeezed correlations of $\phi$ meson pairs for hydrodynamic sources in high-energy heavy-ion collisions

TL;DR

This paper investigates squeezed back-to-back correlations of phi meson pairs in hydrodynamic models of high-energy heavy-ion collisions, revealing oscillatory behaviors and directional dependencies as key signatures.

Contribution

It provides the first detailed calculation of BBC functions for hydrodynamic sources with ($2+1$)D evolution, highlighting their oscillations and angular dependencies.

Findings

BBC functions exhibit oscillations as a function of particle momentum.

BBC functions depend on azimuthal angles and pseudorapidity, showing minimum at certain angles.

Oscillations and angular dependencies are potential signatures for detecting BBC in experiments.

Abstract

In the hot and dense hadronic sources formed in high-energy heavy-ion collisions, the particle interactions in medium might lead to a squeezed back-to-back correlation (BBC) of boson-antiboson pairs. We calculate the BBC functions of $\phi\phi$ for sources evolving hydrodynamically in ($2+1$) dimensions and with longitudinal boost invariance. The BBC functions for hydrodynamic sources exhibit oscillations as a function of the particle momentum because the temporal distributions of hydrodynamic sources have sharp falls to 0 at large evolving times. The dependences of the BBC functions on the directions of the particle momentum are investigated. For transverse anisotropic sources, the BBC functions are minimum when the azimuthal angles of the particles reach 0. The BBC functions increase with decreasing absolute value of the particle pseudorapidity. The oscillations and the dependences on the particle azimuthal angle and pseudorapidity are the significant signatures for detecting the BBC in high-energy heavy-ion collisions.