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T: Fachverband Teilchenphysik
T 36: Top-Quark: Zerfälle
T 36.6: Talk
Friday, March 2, 2012, 10:00–10:15, ZHG 104
HEPTopTagger Subjet Calibration for ATLAS — •Sebastian Schätzel, Gregor Kasieczka, André Schöning, and David Sosa — Physikalisches Institut, Universität Heidelberg
The HEPTopTagger is an algorithm that tries to identify hadronically decaying top quarks on an event-by-event basis [1]. It reconstructs the top quark four-momentum by combining the two decay jets of the W boson with the jet from the tW-vertex. As a measure against pile-up and underlying event, a filtering step is applied which involves running the Cambridge/Aachen (C/A) jet algorithm with a dynamically chosen radius that adapts to the distance between the particles. The C/A jets have to be well calibrated to obtain high tagging efficiency and background rejection. The talk describes the energy calibration of the C/A jets for the ATLAS detector.
[1] Plehn et al., Stop Reconstruction with Tagged Tops, JHEP10 (2010) 078