Measurement of jet pT correlations in Pb + Pb and pp collisions at sNN=2.76 TeVwith the ATLAS detector

Summary, in English

Measurements of dijet pT correlations in Pb+Pb and pp collisions at a nucleon–nucleon centre-of-mass energy of sNN=2.76 TeV are presented. The measurements are performed with the ATLAS detector at the Large Hadron Collider using Pb+Pb and pp data samples corresponding to integrated luminosities of 0.14 nb−1 and 4.0 pb−1, respectively. Jets are reconstructed using the anti-kt algorithm with radius parameter values R=0.3 and R=0.4. A background subtraction procedure is applied to correct the jets for the large underlying event present in Pb+Pb collisions. The leading and sub-leading jet transverse momenta are denoted pT1 and pT2. An unfolding procedure is applied to the two-dimensional (pT1,pT2) distributions to account for experimental effects in the measurement of both jets. Distributions of (1/N)dN/dxJ, where xJ=pT2/pT1, are presented as a function of pT1 and collision centrality. The distributions are found to be similar in peripheral Pb+Pb collisions and pp collisions, but highly modified in central Pb+Pb collisions. Similar features are present in both the R=0.3 and R=0.4 results, indicating that the effects of the underlying event are properly accounted for in the measurement. The results are qualitatively consistent with expectations from partonic energy loss models. © 2017 The Author

• Author: M Aaboud; Torsten Åkesson; Simona Bocchetta; Lene Bryngemark; Caterina Doglioni; Vincent Hedberg; Göran Jarlskog; Charles Kalderon; Else Lytken; Ulf Mjörnmark; Oxana Smirnova; Oleksandr Viazlo
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2017
• Language: English
• Pages: 379-402
• Publication/Series: Physics Letters B
• Volume: 774
• Links: http://dx.doi.org/10.1016/j.physletb.2017.09.078
• Document type: Journal article
• Publisher: Elsevier
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 0370-2693