报告题目：Probing QCD collectivity at the smallest scale through high multiplicity jets in pp collisions at CMS
报告人：刘潇屿 Postdoctoral Associate (莱斯大学）
报告时间：2025年5月29日 下午2：00-3:30
报告地点：理8栋118报告厅
报告摘要：
Recent CMS data have revealed long-range correlations at high in-jet charged particle multiplicity (
) within jets produced in proton-proton (pp) collisions, suggesting collective behavior in systems much smaller than those typical of heavy ion collisions. In the polar coordinate system about the reconstructed jet axis, two-particle azimuthal correlations show an unexpected rise in elliptic anisotropy (
) at large pseudorapidity separations (
) as a function of 
, a trend not reproduced by event generators like PYTHIA or SHERPA. In this seminar, I will present detailed measurements of long-range correlations using LHC Run 2 data at 
TeV and compare the results with model predictions. The transverse momentum and 
dependence of 
is showed across a wide range in 
. Furthermore, the role of jet substructure, particularly in jets exhibiting two-prong features, is examined to unveil a potential connection between the 
enhancement and the initial-state jet geometry. A surprising increase in 
emerges exclusively in those two-prong jets at high 
.
报告人简介：
刘潇屿，莱斯大学（Rice University）博士后研究员。2017年本科毕业于华中师范大学，2023博士毕业于俄亥俄州立大学（The Ohio State University）。博士期间主要参与RHIC-STAR实验，研究内容包括利用Event Plan Detector (EPD) 在大赝快区域测量directed flow，以及在RHIC BES-II能区研究flow decorrelation现象。2024年起加入LHC-CMS实验，研究兴趣包括喷注中的集体行为和CMS二期升级相关课题。