Quark Matter 2025

Session

Parallel session 12

8 Apr 2025, 08:40

Goethe University Frankfurt, Campus Westend, Theodor-W.-Adorno-Platz 1, 60629 Frankfurt am Main, Germany

Conveners

Parallel session 12: Collective dynamics & small systems I

• Ulrich Heinz

788. Measurement of directed flow of $K^{*0}$ and $\phi$ Resonances in Au+Au collisions at RHIC BES energies

Md. Nasim (University of California, Los Angeles)

08/04/2025, 08:40

Collective dynamics & small systems

Oral

It is known from earlier studies that the hadronic interaction affects the measured yield of short lived resonance e.g. $K^{*0}$. Recent studies [1] show that the directed flow ($v_{1}$) of $K^{*0}$ is strongly affected during the hadronic stage due to asymmetric loss in different sides of the $p_{x}$ axis in momentum space caused by the tilted fireball and density dependent rescattering....

440. Recent flow and correlation measurements from ATLAS in $pp$, $p$+Pb and Pb+Pb collisions

Tomasz Bold (AGH University of Krakow (PL))

08/04/2025, 09:00

Collective dynamics & small systems

Oral

This talk presents recent ATLAS measurements investigating correlations between the 'ridge' - azimuthal correlations between particles in the underlying event that extend over all rapidities - and hard scattering processes in $pp$ and $p$+Pb collisions. To study this soft-hard correlation, measurements of two-particle correlations in with two different particle-pair selections are studied. In...

25. Long-range near-side correlation in e+e- collisions at 183-209 GeV with ALEPH archived data

Michael Joseph Peters (Massachusetts Inst. of Technology (US))

08/04/2025, 09:20

Collective dynamics & small systems

Oral

The first measurement of two-particle angular correlations for charged particles with LEP-II data is presented. The study is performed using archived hadronic $e^+e^-$ data collected by ALEPH at center-of-mass energies up to 209 GeV, above the $WW$ production threshold, which provide access to unprecedented charged-particle multiplicities and more complex color-string configurations if...

46. What happens in hydrodynamic simulations of heavy-ion collisions when causality is violated?

Lorenzo Gavassino

08/04/2025, 09:40

Collective dynamics & small systems

Oral

It was recently discovered that Israel-Stewart theory is not as causal as we thought [1]. When a fluid expands too fast, as in heavy ion simulations at early times, the large viscous stresses modify the propagation speeds, leading to superluminal signaling [2]. Since we would not trust hydrodynamic information speeds anyway, this may not sound like such disconcerting news, were it not for some...

9. EPJ Featured Talk: Transport Coefficients from pQCD to the Hadron Resonance Gas at finite BSQ densities

Ms Isabella Danhoni

08/04/2025, 10:00

Collective dynamics & small systems

Oral

We present calculations of the shear viscosity in two limits using perturbative QCD and an excluded-volume hadron resonance gas at finite BSQ densities. We then develop a framework that interpolates these two limits to calculate shear viscosity across a wide range of finite BSQ densities. The pQCD and hadron resonance gas calculations have different BSQ densities dependence, leading to a...