Heidelberg 2022 – scientific programme
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T: Fachverband Teilchenphysik
T 70: Experimental Methods (general) 3
T 70.6: Talk
Wednesday, March 23, 2022, 17:30–17:45, T-H29
Signal efficiency corrections for boosted X→ bb tagger using Z→ bb events with the ATLAS experiment — •Daariimaa Battulga, Arely Cortes Gonzalez, and Cigdem Issever — Institut für Physik, Humboldt-Universität zu Berlin
It is of utmost interest to efficiently identify a new heavy resonant particle or to study boosted Higgs boson decaying into a pair of b-quarks in the ATLAS experiment. Particles produced with high transverse momentum (pT) will have very collimated decay products in the final state. This boosted topology makes it particularly challenging to distinguish two b-jets in the calorimeter. To overcome this, these b-jet fragmentations are clustered within a large radius R=1.0 jet, and its associated track jets are b-tagged. However, even with this approach, the double b-tagging efficiency decreases at the large pT. The boosted X→ bb tagger improves the efficiency of the b-tagging at the higher pT region. This double b-tagger is based on the neural network that uses the kinematic distributions of the large-R jet and flavour information of variable radius track jets. In order to apply this X→ bb tagger to the physics analysis, it needs a dedicated calibration.
Hence, this talk presents the in situ signal efficiency calibrations of a new X→ bb tagger using Z→ bb events. We have derived the data-to-simulation scale factors using full Run 2 pp collision data collected by the ATLAS experiment at the center of mass energy of √s=13 TeV with an integrated luminosity of L=139 fb−1. The signal efficiency corrections covering the soft (hard) pT region are derived using Z→ bb events with a recoiling photon (jets).