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Search for heavy pseudoscalar and scalar bosons decaying to a top quark pair in proton-proton collisions at √s = 13 TeV

The CMS collaboration; Makarenko, V.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Benato, L.; Bergauer, T.; Dragicevic, M.; Giordano, C.; Hussain, P. S.; Jeitler, M.; Krammer, N.; Li, A.; Liko, D.; Matthewman, M.; Mikulec, I.; Schieck, J.; Schöfbeck, R.; Schwarz, D.; ... mehr

Abstract:

A search for pseudoscalar or scalar bosons decaying to a top quark pair ($t\overline{t}$) in final states with one or two charged leptons is presented. The analyzed proton–proton collision data was recorded at $\sqrt{s}$ = 13 TeV by the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 138 fb$^{−1}$. The invariant mass m$_{t\overline{t}}$ of the reconstructed $t\overline{t}$ system and variables sensitive to its spin and parity are used to discriminate against the standard model $t\overline{t}$ background. Interference between pseudoscalar or scalar boson production and the standard model $t\overline{t}$ continuum is included, leading to peak-dip structures in the m$_{t\overline{t}}$ distribution. An excess of the data above the background prediction, based on perturbative quantum chromodynamics (QCD) calculations, is observed near the kinematic $t\overline{t}$ production threshold, while good agreement is found for high m$_{t\overline{t}}$. The data are consistent with the background prediction if the contribution from a simplified model of a color-singlet $^1$S$^{[1]}_0$ $t\overline{t}$ quasi-bound state $η_t$, inspired by nonrelativistic QCD, is added. ... mehr


Originalveröffentlichung
DOI: 10.48550/arXiv.2507.05119
Zugehörige Institution(en) am KIT Institut für Astroteilchenphysik (IAP)
Institut für Experimentelle Teilchenphysik (ETP)
Institut für Prozessdatenverarbeitung und Elektronik (IPE)
Scientific Computing Center (SCC)
Publikationstyp Forschungsbericht/Preprint
Publikationsjahr 2025
Sprache Englisch
Identifikator KITopen-ID: 1000193504
Vorab online veröffentlicht am 07.07.2025
Nachgewiesen in arXiv
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