Aachen 2019 – scientific programme

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T: Fachverband Teilchenphysik

T 82: Flavor-Tagging, Jet-Kalibration

T 82.2: Talk

Thursday, March 28, 2019, 16:15–16:30, S09

Overview of b-tagging and its calibration in the ATLAS collaboration — •Matthieu Robin — DESY-Zeuthen, Germany

Flavour tagging is used to discriminate different flavours in jets. So called b-taggers are important tools for the identification of bottom quark jets (e.g.: Higgs measurements and SUSY searches).

These algorithms calculate a single discriminating variable based on B-hadron specific properties using a combination of different algorithms. This allows to estimate how likely a jet is to include a b-quark.

Discrepancies are observed between the Monte Carlo simulations and the data due to mismodelling. Therefore a calibration of the b-tagging algorithm is performed applying scale factors on the simulations. This ensures that the b-tagging response in Monte Carlo simulations agrees with the response in data. The algorithm output is used applying a fixed cut or in a binned distribution (5 bins). Several methods are performed for the calibrations of the b-tagging efficiency and the mistag rate of light and charm jets.

The aim is to present how the calibration scale factors are extracted from template fits to the data and made available for common ATLAS analysers in a dedicated format.