Search for a light charged Higgs boson in t → H±b decays, with H± → cb, in the lepton+jets final state in proton-proton collisions at s = 13 TeV with the ATLAS detector

• Published in: The journal of high energy physics 2023-09, Vol.2023 (9), p.4
• Main Authors: Abbott, B., Abbott, D. C., Ahmed, W. S., Alhroob, M., Ananiev, V., Anastopoulos, C., Beringer, J., Bertram, I. A., Bitadze, A., Bobrovnikov, V. S., Bokan, P., Bouaouda, K., Bouquet, R., Brandt, O., Bussey, P. J., Camacho Toro, R., Carnesale, M., Celli, F., David, C., De Vivie De Regie, J. B., Delmastro, M., Derkaoui, J. E., D’Onofrio, M., Doria, A., Du, D., Elmsheuser, J., Fabbri, L., Fadeyev, V., Filthaut, F., Garonne, V., Gkialas, I., Gonski, J. L., Gonzalez-Sevilla, S., Guida, A., Guth, M., Han, L., Heinemann, B., Helary, L., Hessey, N. P., Hodkinson, B. H., Huseynov, N., Ingebretsen Carlson, T., Kagan, H., Kiehn, M., Kirk, J., Konya, B., Kordas, K., Kumar, M., Lari, T., Lenz, T., Leopold, A., Liu, K., Luise, I., Ma, Y., Mandić, I., Manthos, I., Matakias, D., Meadows, Z. A., Mehlhase, S., Morettini, P., Mosidze, M., Mullin, J. J., Muškinja, M., Nachman, B. P., Ochi, A., Oliveira Damazio, D., Olszowska, J., Palacino, G., Ragusa, F., Rej, A., Roland, B., Rovelli, G., Saha, S., Schwienhorst, R., Seidlitz, B. D., Sekula, S. J., Shaked Renous, D., Shimmin, C. O., Shipsey, I. P. J., Siegert, F., Simsek, S., Smirnov, Y., Solovyev, V., Standke, M., Stanitzki, M. M., Stewart, G. A., Strandberg, S., Sulin, V. V., Trischuk, D. A., Tsuno, S., Vazquez Furelos, D., Vorobev, K., Vozak, M., Wang, C., Wilkens, H. G., Xiao, X., Xu, D., Zenin, O., Zhang, L., Zhang, S.
• Format: Article
• Language: English
• Subjects: Charm (particle physics); Classical and Quantum Gravitation; Collisions; Confidence intervals; Elementary Particles; Hadrons; Higgs bosons; High energy physics; Jets; Kinematics; Large Hadron Collider; Leptons; Luminosity; Neural networks; Pair production; Physics; Physics and Astronomy; Protons; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Quarks; Regular Article - Experimental Physics; Relativity Theory; Searching; String Theory; Topology
• ISSN: 1029-8479
• DOI: 10.1007/JHEP09(2023)004

A bstract A search for a charged Higgs boson, H ± , produced in top-quark decays, t → H ± b , is presented. The search targets H ± decays into a bottom and a charm quark, H ± → cb . The analysis focuses on a selection enriched in top-quark pair production, where one top quark decays into a leptonically decaying W boson and a bottom quark, and the other top quark decays into a charged Higgs boson and a bottom quark. This topology leads to a lepton-plus-jets final state, characterised by an isolated electron or muon and at least four jets. The search exploits the high multiplicity of jets containing b -hadrons, and deploys a neural network classifier that uses the kinematic differences between the signal and the background. The search uses a dataset of proton-proton collisions collected at a centre-of-mass energy s = 13 TeV between 2015 and 2018 with the ATLAS detector at CERN’s Large Hadron Collider, amounting to an integrated luminosity of 139 fb − 1 . Observed (expected) 95% confidence-level upper limits between 0.15% (0.09%) and 0.42% (0.25%) are derived for the product of branching fractions B ( t → H ± b ) × B ( H ± → cb ) for charged Higgs boson masses between 60 and 160 GeV, assuming the SM production of the top-quark pairs.