2026-10-19T00:34:11Zhttps://ebyu-rdlopen.rawdatalibrary.net/oai/requestoai:ebyu-rdlopen.rawdatalibrary.net:ebyu/105802026-10-18T20:25:46Zopenairedrivercom_ebyu_10000col_ebyu_10001Search for heavy pseudoscalar and scalar bosons decaying to a top quark pair in proton-proton collisions at √s = 13 TeVHayrapetyan, A.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.Shooshtari, M.Sonawane, M.Waltenberger, W.Wulz, C.-E.Janssen, T.Kwon, H.Ocampo Henao, D.Van Laer, T.Van Mechelen, P.Bierkens, J.Breugelmans, N.D'Hondt, J.Dansana, S.De Moor, A.Delcourt, M.Heyen, F.Hong, Y.Kashko, P.Lowette, S.Makarenko, I.Müller, D.Song, J.Tavernier, S.Tytgat, M.Van Onsem, G.P.Van Putte, S.Vannerom, D.Bilin, B.Clerbaux, B.Das, A.K.De Bruyn, I.CMSpseudoscalar bosonscalar bosontop quarkA search for pseudoscalar or scalar bosons decaying to a top quark pair (tt¯) in final states with one or two charged leptons is presented. The analyzed proton-proton collision data was recorded at √s = 13 TeV by the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 138 fb-1. The invariant mass mtt¯ of the reconstructed tt¯ system and variables sensitive to its spin and parity are used to discriminate against the standard model tt¯ background. Interference between pseudoscalar or scalar boson production and the standard model tt¯ continuum is included, leading to peak-dip structures in the mtt¯ distribution. An excess of the data above the background prediction, based on perturbative quantum chromodynamics (QCD) calculations, is observed near the kinematic tt¯ production threshold, while good agreement is found for high mtt¯. The data are consistent with the background prediction if the contribution from a simplified model of a color-singlet 1S[1]0 tt¯ quasi-bound state ηt, inspired by nonrelativistic QCD, is added. Upper limits at 95% confidence level are set on the coupling between the pseudoscalar or scalar bosons and the top quark for boson masses in the range 365.1000 GeV, relative widths between 0.5% and 25%, and two background scenarios with or without ηt contribution. © 2025 The Author(s). Published by IOP Publishing Ltd.Institute of Physics2025Articlehttps://rdlopen.rawdatalibrary.net/r/ebyu/10580https://doi.org/10.1088/1361-6633/ae22070034-4885enReports on Progress in Physicsinfo:eu-repo/semantics/openAccessinfo:eu-repo/semantics/articlehttps://ebyu-rdlopen.rawdatalibrary.net/tr/items/ebyu/10580