Aachen 2019 – scientific programme

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T: Fachverband Teilchenphysik

T 83: Top-Physik III

T 83.2: Talk

Thursday, March 28, 2019, 16:15–16:30, S10

Measurement of the top quark mass in the all-jets final state at √s=13 TeV and combination with the lepton+jets channel — Christoph Garbers, •Johannes Lange, Peter Schleper, and Hartmut Stadie — Institut für Experimentalphysik, Universität Hamburg

The top quark mass m_t is measured using 35.9 fb⁻¹ of proton-proton collision data collected with the CMS experiment at the LHC at √s=13 TeV. The tt all-jets final state is used, i.e., events consisting of at least six jets are selected. The full tt system is reconstructed using a kinematic fit, allowing to improve the mass resolution and suppress multijet background. An estimation of the remaining background is performed using data events. Using the ideogram method, m_t is extracted, simultaneously constraining an additional jet energy scale factor.

In addition, a combined measurement using the all-jets and lepton+jets final states is presented. The likelihoods for both channels are combined and a simultaneous mass extraction is performed.

Differences in the determination of systematic uncertainties with respect to previous results obtained at √s=7 and 8 TeV are discussed.