Welcom

• Zhenyu Chen (Shandong University (CN))

Experimental overview - RHIC

• Fuqiang Wang (Purdue University (US))

Experimental overview - LHC

• You Zhou (Niels Bohr Institute (DK))

Hyperon polarization in pPb collisions

• Chenyan Li (Shandong University (CN))

Dynamical core-corona initialization in small colliding systems

• Tetsufumi Hirano

Hydro Overview 2

• Huichao Song

EPOS Overview

• Klaus WERNER (subatech)
• Klaus WERNER

AMPT Overview

• Zi-Wei Lin (East Carolina University)

Collectivity in small systems from a multi-phase transport model point of view

• Liang Zheng (China University of Geosciences (CN))

The striking collectivity like behavior found in high-multiplicity proton-proton (pp) collisions and ultra-peripheral collisions (UPC) at the LHC challenges our conventional wisdom on the formation of the quark-gluon plasma (QGP). A microscopic explanation to the origin of collectivity in these collision systems at rather small scales will help us understand the mechanism that leads to the QGP-like signals in small systems. In our recent work, we have coupled PYTHIA8 initial conditions with sub-nucleon spatial fluctuations to the final state parton and hadron interactions and quark coalescence of the string melting AMPT model to study the small system collective effects. In this approach, the AMPT initial condition originally provided by HIJING is replaced by the PYTHIA/Angantyr model and includes the sub-nucleon structure for the struck nucleon and photon. We have found that the collective flow features in small collision systems can be well described by the AMPT model with sub-nucleon spatial fluctuation, indicating its importance for the small system evolution. In this talk, we will present these model results and comparisons to the experimental data.

Discussion

PYTHIA Overview

• Leif Lönnblad (Lund University (SE))

Initial State Overview

• Oscar Garcia-Montero

Collectivity in DIS/photo-production/UPC

• Nicole Lewis (Rice University (US))

Collectivity in e+e- (remote)

• Yen-Jie Lee (Massachusetts Inst. of Technology (US))

Collectivity in jets: exp

• Austin Alan Baty (University of Illinois Chicago)

Collectivity in jets: theory (remote)

• Wenbin Zhao (Wayne State University)

Investigating the elliptic anisotropy of hard probes in small collision systems

• Siyu Tang (Central China Normal University CCNU (CN))

Understanding non-flow in small systems talk1

• Yicheng Feng (Purdue University)

Understanding non-flow in small systems talk2

• Sanghoon Lim (Pusan National University (KR))

Understanding non-flow in small systems talk3

• Jiangyong Jia (Stony Brook University (US))

Discussion

OO and nuclear structure in small systems

• Shengli Huang

Impact of nuclear structure on collectivity in small collision systems

• Chunjian Zhang (Stony Brook University)

Mapping of the nuclear structure on the small and medium-sized systems via collectivity

• Xinli Zhao (Shanghai Institute of Applied Physics, Chinese Academy of Scien)
• Xinli Zhao

Theory overview of nuclear structure in small system

• Giuliano Giacalone (Universität Heidelberg)

Speed of sound: exp

• Cesar Bernardes (UNESP - Universidade Estadual Paulista (BR))

Speed of sound: theory1

• Wilke Van Der Schee (CERN)

Speed of sound: theory2

• Govert Hugo Nijs (CERN)

Flow decorrelation in small systems

• Yuko Sekiguchi (University of Tokyo (JP))

3D modeling of small system collisions from RHIC to LHC

• Chun Shen (Wayne State University)

Jet quenching in small sized systems: exp

• Peter Martin Jacobs (Lawrence Berkeley National Lab. (US))

Multiparticle vn at high pT in small system from CMS

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

Jet quenching and RAA in small systems: theory

• Isobel Kolbe (University of the Witwatersrand (ZA))

Heavy flavor production and collectivity in small system: exp

• Wei Xie (Purdue University (US))

Study of Upsilon(1S) flow in CMS

• Kisoo Lee (Korea University (KR))

The second-order Fourier coefficients ($v_2$) are expected to reflect the overlap region of colliding heavy ions. However, a non-zero $v_2$ has been observed in high-multiplicity pp and pPb collisions where overlap does not exist. The CMS experiment collected data at a nucleon-nucleon center-of-mass energies 5.02 and 8.16 TeV for PbPb and pPb collisions, respectively. The dimuons were used to reconstruct the $\mathrm{{\rm Y}}$(1S) mesons. The Q-vector method is used for PbPb collisions while the long-range two-particle correlation technique is used for pPb collisions. The measurement of the $\mathrm{{\rm Y}}$(1S) $v_2$ is reported for both heavy ion and small collision systems. The results are discussed in the context of collectivity and modification of heavy quark dynamics.

Measurements of quarkonia suppression in small system in CMS with LHC Run2 data

• Soohwan Lee (Korea University (KR))

Quarkonium production in small systems has been extensively studied in LHC and RHIC to understand the suppression effects which may be described by the existence of a small QGP droplet. To further elaborate, it is necessary to obtain experimental data where models can describe the suppression from the hot medium effect and the cold nuclear matter effect. In this talk, we present recent studies of quarkonia in CMS using pp and pPb collision data taken from LHC in Run 2. We will focus on the nuclear suppression $R_{\mathrm{p}\mathrm{P}\mathrm{b}}$ for charmonia and bottomonia and compare our results with theoretical model predictions.

Study of quarkonia suppression in pO and OO with SHINCHON MC

• Yongsun Kim (Sejong University (KR))

charmonium collective flows in nuclear collisions: (directed, elliptic, triangular) flows

• Baoyi Chen (Tianjin University)

We employ a detailed transport model coupled with realistic hydrodynamics in heavy-ion collisions to study the anisotropic flows of charmonium, including directed flow, elliptic flow, and triangular flows. The directed flow ($v_1$) of $J/\psi$ is induced by the rapidity-odd initial energy density, which arises from the rotation of the quark-gluon plasma (QGP). Meanwhile, the elliptic flow ($v_2$) of $J/\psi$ primarily depends on two factors: the initial spatial energy density in the nuclear collision region and the degree of thermalization of charm kinetics. The triangular flow of $J/\psi$ originates from the triangular flows of charm quarks, which acquire anisotropic flows from the surrounding bulk medium with fluctuating initial energy densities. These anisotropic flows ($v_1,v_2,v_3$) of $J/\psi$ contribute to our understanding of the detailed evolutions of charm and charmonium in the fluctuating and rotational QGP.

Discussion

Banquet

Anisotropic flow and the valence quark skeleton of hadrons

• Hong Zhang

Unraveling QGP and jet physics via perturbing attractors

• Xin An (National Center for Nuclear Research)

The rapid longitudinal expansion characteristic of heavy-ion collisions leads to universal attractor behavior of the resulting drop of Quark-Gluon Plasma already at very early times. Assuming approximate boost invariance, we incorporate transverse dynamics and parton evolution by linearizing the Mueller-Israel-Stewart theory around the attractor. This yields a system of coupled ordinary differential equations which describe the proper-time evolution of perturbations encoding the transverse structure of the initial and jet energy deposition across a wide range of geometric configurations and parton energy loss scenarios. The late-time asymptotic behavior of the solutions is described by transseries which manifest the stability of the attractor against transverse perturbations, as well as a dominant power-law series attributed to the parton source. Although most of the physically relevant initial information resides in the exponentially suppressed transseries corrections to the evolution along the attractor, they are not yet negligible at freeze-out. These findings advocate for a simple numerical approach to QGP dynamics which accounts for the transverse dynamics and jet-medium interactions via a finite set of Fourier modes. Physical observables can be expressed in terms of the asymptotic data evaluated at freeze-out. We demonstrate the efficacy of this approach in describing key observables such as collectivity across various system scales, as well as the consequential effects of jet wakes.

Multi-particle cumulants from transverse momentum conservation and flow

• Jialin Pei (Fudan University)

EicC Overview

• yuxiang zhao

Closing remarks

• Zhenyu Chen (Shandong University (CN))