Tea Time学术活动系列邀请报告(139)

(University of Belgrade, Vinca Institute of Nuclear Sciences)

The $v_{2}$ and $v_{3}$ harmonics in PbAu collisions at 17.3 GeV are measured using the event plane method. Two-dimensional two-particle correlations are used to extract $v_{n}$ harmonics up to the 7-th order from ultra-central PbPb collisions at the LHC energy. The same method is used to study anisotropies in small systems formed in pp, pPb and peripheral PbPb collisions. Beside the appearance of the higher order harmonics, the initial-state fluctuations also induce transverse momentum ($p_{T}$) and pseudorapidity ($\eta$) dependence of the event plane which leads to so called factorization breaking. It is studied in pPb and PbPb collisions at the LHC energies. A relatively new method of Principal Component Analysis (PCA) is used to show the existence of the sub-leading flow modes of the $v_{2}$ and $v_{3}$ harmonics in pPb and PbPb collisions at the LHC energies. They are connected with the factorization breaking, and Pearson coefficients, extracted from the sub-leading flow modes are in a rather good agreement with the standardly measured factorization breaking. The HYDJET++ model shows the existence of the sub-leading flow modes in PbPb collisions, and they are in a good agreement with the experimental data. Also, skewness of the elliptic flow distributions measured using the method of cumulants in HYDJET++ simulations are in a rather good agreement with the experimental results. The correlations between the $v_{2}$, $v_{3}$ and $v_{4}$ harmonics are studied by the AMPT and HYDJET++ model. The AMPT model shows a good agreement with the experimental data, while it is not the case for the HYDJET++ predictions.

Jovan Milosevic塞尔维亚贝尔格莱德大学教授、Vinca核科学研究所研究员，2003年在德国海德堡大学取得博士学位，2003-2010年分别在德国海德堡大学和挪威奥斯陆大学从事博士后研究工作。目前是欧洲核子研究中心大型强子对撞机LHC上CMS实验组的合作成员，长期致力于相对论重离子碰撞的实验和唯象研究，在重离子碰撞中各向异性流、碰撞中喷注与集体效应相互作用等领域有丰富的研究成果，已在Phys. Rev. Lett., Phys. Lett. B, Phys. Rev. C, Nucl. Phys. A, JHEP等学术刊物上发表SCI论文50余篇。