Analysis of pion elliptic flow and Hanbury-Brown–Twiss interferometry in a granular quark-gluon plasma droplet model

Abstract

In many simulations of high-energy heavy-ion collisions on an event-by-event analysis, it is known that the initial energy density distribution in the transverse plane is highly fluctuating. Subsequent longitudinal expansion will lead to many longitudinal tubes of quark-gluon plasma which have tendencies to break up into many spherical droplets because of sausage instabilities. We are therefore motivated to use a model of quark-gluon plasma granular droplets that evolve hydrodynamically to investigate pion elliptic flows and Hanbury-Brown-Twiss interferometry. We find that the data of pion transverse momentum spectra, elliptic flows, and HBT radii in √ sNN = 200 GeV Au + Au collisions at RHIC can be described well by an expanding source of granular droplets with an anisotropic velocity distribution.

Interferometry for rotating sources

“…Thus the model results show that rotation significantly influences the HBT evaluation similarly like the expansion, which influences data significantly, e.g. in publications [21][22][23][24][25].…”

Two-Pion Interferometry for the Granular Sources in Ultrarelativistic Heavy Ion Collisions at the RHIC and the LHC

“…1 of Ref. [10]) due to the "sausage" instability and surface tension. [10] However, the rapidly increased bulk viscosity in the QGP near the phase transition may also lead to the breakup of the system.…”

“…In Refs. [10,11], the granular source model of quark-gluon plasma (QGP) droplets [12] is developed to explain the RHIC HBT data. [7,8] In this work we investigate the two-pion HBT interferometry in ultrarelativistic heavy ion collisions in the granular source model of QGP droplets.…”

“…[10]) due to the "sausage" instability and surface tension. [10] However, the rapidly increased bulk viscosity in the QGP near the phase transition may also lead to the breakup of the system. [18] We assume that the system fragments and forms a granular source of many QGP droplets at a time 𝑡 0 (> 𝜏 0 ).…”

“…In our model calculations, the initial droplet radius in the droplet local frame satisfies a Gaussian distribution with standard deviation 𝜎 𝑑 and the initial droplet centers are assumed to distribute within a cylinder along the beam direction by [10,11]…”