Centrality and pseudorapidity dependence of the transverse energy density in pPb collisions ats root s(NN)=5.02 TeV

• Main Authors: Sirunyan, A. M., Tumasyan, A., Adam, Wolfgang, Ambrogi, Federico, Asilar, Ece, Md. Ali, Mohd. Adli
• Format: Article
• Language: English; English; English
• Published: American Physical Society 2019
• Subjects: Q Science (General); QC Physics
• Online Access: http://irep.iium.edu.my/80162/19/80162_Centrality%20and%20pseudorapidity%20dependence%20of%20the%20transverse_article%20%28%20CMS%20project%29.pdf; http://irep.iium.edu.my/80162/2/80162_Centrality%20and%20pseudorapidity%20dependence_scopus.pdf; http://irep.iium.edu.my/80162/3/80162_Centrality%20and%20pseudorapidity%20dependence_wos.pdf; http://irep.iium.edu.my/80162/; https://journals.aps.org/prc/pdf/10.1103/PhysRevC.100.024902

The almost hermetic coverage of the CMS detector is used to measure the distribution of transverse energy, ET, over 13.2 units of pseudorapidity, η, for pPb collisions at a center-of-mass energy per nucleon pair of √sNN = 5.02 TeV. The huge angular acceptance exploits the fact that the CASTOR calorimeter at −6.6 <η< −5.2 is effectively present on both sides of the colliding system because of a switch in the proton-going and lead-going beam directions. This wide acceptance enables the study of correlations between well-separated angular regions and makes the measurement a particularly powerful test of event generators. For minimum bias pPb collisions the maximum value of dET/dη is 22 GeV, which implies an ET per participant nucleon pair comparable to that of peripheral PbPb collisions at √sNN = 2.76 TeV. The increase of dET/dη with centrality is much stronger for the lead-going side than for the proton-going side. The η dependence of dET/dη is sensitive to the η range in which the centrality variable is defined. Several modern generators are compared to these results but none is able to capture all aspects of the η and centrality dependence of the data and the correlations observed between different η regions