The European Physical Journal C

, Volume 62, Issue 1, pp 191–196 | Cite as

Identification and rejection of fake reconstructed jets from a fluctuating heavy ion background in ATLAS

Open Access
Regular Article - Experimental Physics

Abstract

Full jet reconstruction in relativistic heavy ion collisions provides new and unique insights to the physics of parton energy loss. Because of the large underlying event multiplicity in A+A collisions, random and correlated fluctuations in the background can result in the reconstruction of fake jets. These fake jets must be identified and rejected to obtain the purest jet sample possible. A large but reducible fake rate of jets reconstructed using an iterative cone algorithm on HIJING events is observed. The absolute rate of fake jets exceeds the binary-scaled p+p jet rate below 50 GeV and is not negligible until 100 GeV. The variable Σj T , the sum of the jet constituent’s E T perpendicular to the jet axis, is introduced to identify and reject fake jets at by a factor of 100 making it negligible. This variable is shown to not strongly depend on jet energy profiles modified by energy loss. By studying azimuthal correlations of reconstructed di-jets, the fake jet rate can be evaluated in data.

Keywords

Large Hadron Collider Atlas Collaboration Atlas Detector Azimuthal Correlation Parton Energy Loss 

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Copyright information

© Springer-Verlag / Società Italiana di Fisica 2009

Authors and Affiliations

  1. 1.Columbia UniversityNew YorkUSA

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