Home > Research > Publications & Outputs > Observation of Associated Near-Side and Away-Si...
View graph of relations

Observation of Associated Near-Side and Away-Side Long-Range Correlations in √sNN=5.02  TeV Proton-Lead Collisions with the ATLAS Detector

Research output: Contribution to journalJournal article


  • ATLAS Collaboration
Article number182302
<mark>Journal publication date</mark>1/05/2013
<mark>Journal</mark>Physical Review Letters
Issue number18
Number of pages18
<mark>Original language</mark>English


Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT.

Bibliographic note

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
© 2013 CERN, for the ATLAS Collaboration