Quark Matter 2025

Session

Parallel session 6

10 Apr 2025, 09:00

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

Conveners

Parallel session 6: Collective dynamics & small systems IV

• Jan Steinheimer (Frankfurt Institute for Advanced Studies)

1117. Probing QCD collectivity at the smallest scales through photonuclear collisions and high-multiplicity jets in pp collisions at CMS

Xiaoyu Liu (Rice University (US))

10/04/2025, 09:00

Collective dynamics & small systems

Oral

Recent CMS data revealed intriguing long-range correlations within high-multiplicity jets produced in proton-proton collisions, suggesting the potential onset of collective behavior, typically associated with heavy-ion collisions, at much smaller scales. Two-particle correlations in the “jet frame” show a surprising rise in elliptic flow harmonics, v2, at large pseudorapidity separations (Δη...

944. First measurement of high $p_\mathrm{T}$ azimuthal anisotropy using subevent cumulants in small system collisions at CMS

Rohit Kumar Singh (Indian Institute of Technology Madras (IN))

10/04/2025, 09:20

Collective dynamics & small systems

Oral

Measurements at the LHC have provided evidence for collective behavior in high-multiplicity pp and pPb collisions through multiparticle correlation techniques. However, no conclusive evidence of jet quenching—characterized by the energy loss of high-$p_\mathrm{T}$ partons traversing the medium—have been observed in these smaller systems. This paradox raises an intriguing question: How can a...

843. sPHENIX measurements of collective behavior in small and large systems

Hao-Ren Jheng (Massachusetts Inst. of Technology (US))

10/04/2025, 09:40

Collective dynamics & small systems

Oral

sPHENIX is a next-generation collider detector at RHIC which was successfully commissioned in 2023 and 2024 and took physics data in p+p and Au+Au collisions. In addition to its high-p$_T$ jet and heavy flavor physics program, sPHENIX is a general purpose collider detector with excellent capabilities for exploring collective phenomena in small and large systems. This is due to its large...

410. Longitudinal dynamics of large and small systems from a 3D Bayesian calibration with RHIC top energy data

Andi Mankolli (Vanderbilt University (US))

10/04/2025, 10:00

Collective dynamics & small systems

Oral

Over the past several years, significant progress has been made in leveraging rapidity-dependent measurements from colliders to gain insight about the early and late-time dynamics of relativistic nuclear collisions. In this study, we perform a systematic model-to-data comparison using simulations of Au-Au and $d$-Au collisions and a broad range of measurements from the PHENIX, STAR, PHOBOS,...

786. Hydrodynamization and thermalization in heavy-ion collisions from a kinetic theory perspective

Caio Brito (Universidade Federal Fluminense)

10/04/2025, 10:20

Collective dynamics & small systems

Oral

Understanding the applicability of fluid-dynamical models to describe the hot and dense matter produced in the early stages of hadronic collisions is a fundamental problem in the field. In particular, it is not clear to what degree this hydrodynamization process requires proximity to a local equilibrium state. In this contribution, we study this problem in kinetic theory considering an...