Search for top squarks in events with a Higgs or Z boson using 139 fb-1 of pp collision data at $\sqrt{s}=13$ TeV with the ATLAS detector

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2020-11, Vol.80 (11)
• Main Authors: Abreu, H., Ahmed, W. S., Andrean, S. Y., Pozo, J. Aparisi, Tame, Z. Arrubarrena, Bahmani, M., Baker, O. K., Barillari, T., Barklow, T., Benekos, N., Biesuz, N. V., Brüers, B., Cai, H., Calvet, D., Cetin, S. A., Chekanov, S., Chiarella, V., Cobal, M., Connell, S. H., Cooper-Sarkar, A. M., Cowan, G., Cristinziani, M., Dandoy, J. R., Volpe, D. Della, Demontigny, G., Cornell, S. Díez, Donini, J., Eggleston, M. G., Pastor, O. Estrada, Falke, P. J., Fang, Y., Flores, L., Franchini, M., Gilbert, B. J., Gkialas, I., Goblirsch-Kolb, M., Gutschow, C., Herrmann, T., Huhtinen, M., Imam, H., Isacson, M. F., Ito, F., Jeanty, L., Jinnouchi, O., Jones, T. J., Karava, K., Karpov, S. N., Kay, E. F., Komarek, T., Levêque, J., Li, L., Lytken, E., Lyubushkin, V., Manzoni, S., Martin-Haugh, S., Meshreki, J. R., Martinez, J. Munoz, Nagasaka, Y., Nibigira, E., Nilsson, P., O’Keefe, M. W., Orellana, G. E., Ould-Saada, F., Palni, P., Parker, A. J., Pickles, R. H., Pilcher, J. E., Poggioli, L., Poulsen, T., Proffitt, M. L., Qin, Y., Rej, A., Robertson, S. H., Rozanov, A., Ryzhov, A., Scharmberg, N., Shimogama, Y., Snesarev, A. A., Son, H., Song, W., Stärz, S., Strauss, M., Suzuki, S., Swiatlowski, M., Tackmann, K., Teixeira-Dias, P., Thompson, E. A., Vermeulen, A. T., Wahlberg, H., Wakasa, R., Wardrope, D. R., Weber, M. S., Weingarten, J., Weirich, M., White, A. S., White, A., Wong, V. S., Xu, Z., Zhang, Z., Zhao, P.
• Format: Article
• Language: English
• Subjects: ENGINEERING
• ISSN: 1434-6044; 1434-6052

This paper presents a search for direct top squark pair production in events with missing transverse momentum plus either a pair of jets consistent with Standard Model Higgs boson decay into b-quarks or a same-flavour opposite-sign dilepton pair with an invariant mass consistent with a Z boson. The analysis is performed using the proton–proton collision data at √s=13 TeV collected with the ATLAS detector during the LHC Run-2, corresponding to an integrated luminosity of 139 fb-1. No excess is observed in the data above the Standard Model predictions. The results are interpreted in simplified models featuring direct production of pairs of either the lighter top squark ($\tilde{t}_1$) or the heavier top squark ($\tilde{t}_2$), excluding at 95% confidence level $\tilde{t}_1$ and $\tilde{t}_2$ masses up to about 1220 and 875 GeV, respectively.