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arXiv · 2411.18414

Search for heavy scalar or pseudoscalar states in $\mathrm{t \bar{t}}$ events at CMS

Laurids Jeppe
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Abstract

A search for scalar or pseudoscalar states decaying to a top quark-antiquark pair ($\mathrm{t \bar{t}}$), using $138\,\mathrm{fb}^{-1}$ of pp collision data taken at $\sqrt{s} = 13\,\mathrm{TeV}$ using the CMS detector, is presented. Events with one or two leptons are analyzed using the invariant $\mathrm{t \bar{t}}$ mass ($m_{\mathrm{t \bar{t}}}$) as well as angular and spin correlation observables. An excess in the data is observed for low values of $m_{\mathrm{t \bar{t}}}$, preferring a pseudoscalar over a scalar hypothesis. It is interpreted in terms of a generic model of (pseudo)scalar boson production, as well as a simplified model of a $\mathrm{t \bar{t}}$ bound state ($\eta_{\mathrm{t}}$), yielding good agreement with the data. Moreover, limits on the couplings of additional (pseudo)scalar bosons to top quarks are set.

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Laurids Jeppe. 2024-11-27. Search for heavy scalar or pseudoscalar states in $\mathrm{t \bar{t}}$ events at CMS. https://doi.org/10.21468/scipostphysproc.18.020

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