Münster 2017 – scientific programme

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T: Fachverband Teilchenphysik

T 104: Suche nach neuen Teilchen 5

T 104.2: Talk

Thursday, March 30, 2017, 17:00–17:15, JUR 2

Kinematic fits in tt resonance searches — •Melanie Eich, Johannes Haller, Roman Kogler, and Anastasia Karavdina — Institut für Experimentalphysik, Universität Hamburg

Many extensions of the Standard Model predict new massive gauge bosons (Z′) with an enhanced coupling to top quarks. The experimental signature of such a new boson decaying into a top-quark pair is a resonant structure in the invariant mass of the tt system. While previous searches focussed on high mass resonances with boosted signatures, an extension to low mass resonances with resolved topologies is performed in this work.

In this talk the status of the Z′→ tt search in the lepton+jets channel is presented, using data recorded with the CMS experiment in 2016. A kinematic fit tool is employed, which improves the reconstruction of W bosons and top quarks using measured final state objects, such as jets and leptons. The effect on the resolution of the invariant mass of the tt system is studied and compared to previous reconstruction techniques.