Azimuthal anisotropy of charged particles with transverse momentum up to 100 GeV/c in PbPb collisions at sNN=5.02 TeV

• Main Authors: Sirunyan, A. M., Tumasyan, A. R., Adam, Wolfgang, Asilar, Ece, Bergauer, Thomas, Md. Ali, Mohd. Adli
• Format: Article
• Language: English; English; English
• Published: Elsevier BV 2018
• Subjects: QC Physics; QD Chemistry
• Online Access: http://irep.iium.edu.my/65013/1/65013_Azimuthal%20anisotropy%20of%20charged%20particles_article.pdf; http://irep.iium.edu.my/65013/2/65013_Azimuthal%20anisotropy%20of%20charged%20particles_scopus.pdf; http://irep.iium.edu.my/65013/13/65013_Azimuthal%20anisotropy%20of%20charged%20particles%20with%20transverse%20momentum%20up%20to%20100%20GeVc%20in%20PbPb%20collisions%20at%20sNN_5.02%20TeV_WOS.pdf; http://irep.iium.edu.my/65013/; https://www.sciencedirect.com/science/article/pii/S0370269317309334?via%3Dihub
• Institution: Universiti Islam Antarabangsa Malaysia

The Fourier coefficients v2 and v3 characterizing the anisotropy of the azimuthal distribution of charged particles produced in PbPb collisions at sNN=5.02 TeV are measured with data collected by the CMS experiment. The measurements cover a broad transverse momentum range, 1<pT<100 GeV/c. The analysis focuses on the pT>10 GeV/c range, where anisotropic azimuthal distributions should reflect the path-length dependence of parton energy loss in the created medium. Results are presented in several bins of PbPb collision centrality, spanning the 60% most central events. The v2 coefficient is measured with the scalar product and the multiparticle cumulant methods, which have different sensitivities to initial-state fluctuations. The values from both methods remain positive up to pT∼60–80 GeV/c, in all examined centrality classes. The v3 coefficient, only measured with the scalar product method, tends to zero for pT≳20 GeV/c. Comparisons between theoretical calculations and data provide new constraints on the path-length dependence of parton energy loss in heavy ion collisions and highlight the importance of the initial-state fluctuations.