arXiv subjects

Rolf P. Scharenberg

Publications and source records attributed to Rolf P. Scharenberg.

2 recordsLinked to original sources

arXiv2019

Thermodynamic and transport properties in Au + Au collisions at RHIC energies from the clustering of color strings

In this work, we have extracted the initial tempearture from the transverse momentum spectra of charged particles in $Au+Au$ collisions using STAR data at RHIC energies from $\sqrt{s_{NN}}$ = 7.7 to 200 GeV. The initial energy density ($\varepsilon$), shear viscosity to entropy density ratio ($η/s$), trace anomaly ($Δ$), the squared speed of sound ($C_s^2$), entropy density, and bulk viscosity to entropy density ratio ($ζ/s$) are obtained and compared with the lattice QCD calculations for (2+1) flavor. The initial temperatures obtained are compared with various hadronization and chemical freeze-out temperatures. The analysis of the data shows that the deconfinement to confinement transition possibly takes place between $\sqrt{s_{NN}}$ = 11.5 and 19.6 GeV.

hep-ph↗

arXiv2007

Transverse Momentum Distributions and String Percolation Study in p+p, d+Au and Au+Au at $\sqrt{s_{NN}}$ = 200 GeV

Multiparticle production at high energies is described in terms of color strings stretched between the projectile and target. As string density increases, overlap among the strings leads to cluster formation. At some critical density a macroscopic cluster appears, spanning the entire system. This marks the percolation phase transition. Data from p+p, d+Au and Au+Au collisions at 200 GeV has been analyzed using the STAR detector to obtain the percolation density parameter, $η$. For 200 GeV Au+Au collisions, the value of $η$ is found to lie above the critical percolation threshold, while for 200 GeV d+Au collisions it is below the critical value. This supports the idea of string percolation, which at high enough string density is a possible mechanism to explore the hadronic phase transition to a quark-gluon plasma.

nucl-ex↗