@Article{ATLASCollaborationAad_etal2023, author="ATLAS Collaboration (Aad, G. et al and Akiot, A. and Amos, K. R. and Aparisi Pozo, J. A. and Bailey, A. J. and Bouchhar, N. and Cabrera Urban, S. and Cantero, J. and Cardillo, F. and Castillo Gimenez, V. and Chitishvili, M. and Costa, M. J. and Didenko and Escobar, C. and Fiorini, L. and Fullana Torregrosa, E. and Fuster, J. and Garcia, C. and Garcia Navarro, J. E. and Gomez Delegido, A. J. and Gonzalez de la Hoz, S. and Gonzalvo Rodriguez, G. R. and Guerrero Rojas, J. G. R. and Lacasta, C. and Marti-Garcia, S. and Martinez Agullo, P. and Miralles Lopez, M. and Mitsou, V. A. and Monsonis Romero, L. and Moreno Llacer, M. and Munoz Perez, D. and Navarro-Gonzalez, J. and Poveda, J. and Prades Iba{\~{n}}ez, A. and Rubio Jimenez, A. and Ruiz-Martinez, A. and Sabatini, P. and Salt, J. and Sanchez Sebastian, V. and Sayago Galvan, I. and Senthilkumar, V. and Soldevila, U. and Sanchez, J. and Torro Pastor, E. and Valero, A. and Valls Ferrer, J. A. and Varriale, L. and Villaplana Perez, M. and Vos, M.", title="Search for a new heavy scalar particle decaying into a Higgs boson and a new scalar singlet in final states with one or two light leptons and a pair of $\tau$-leptons with the ATLAS detector", journal="Journal of High Energy Physics", year="2023", publisher="Springer", volume="10", number="10", pages="009--46pp", optkeywords="Hadron-Hadron Scattering", abstract="A search for a new heavy scalar particle X decaying into a Standard Model (SM) Higgs boson and a new singlet scalar particle S is presented. The search uses a proton-proton (pp) collision data sample with an integrated luminosity of 140 fb(-1) recorded at a centre-of-mass energy of root s = 13 TeV with the ATLAS detector at the Large Hadron Collider. The most sensitive mass parameter space is explored in X mass ranging from 500 to 1500 GeV, with the corresponding S mass in the range 200-500 GeV. The search selects events with two hadronically decaying tau-lepton candidates from H -> tau(+)tau(-) decays and one or two light leptons (l = e, mu) from S -> VV (V = W, Z) decays while the remaining V boson decays hadronically or to neutrinos. A multivariate discriminant based on event kinematics is used to separate the signal from the background. No excess is observed beyond the expected SM background and 95{\%} confidence level upper limits between 72 fb and 542 fb are derived on the cross-section sigma(pp -> X -> SH) assuming the same SM-Higgs boson-like decay branching ratios for the S -> VV decay. Upper limits on the visible cross-sections sigma(pp -> X -> SH -> WW tau tau) and sigma(pp -> X -> SH -> ZZ tau tau) are also set in the ranges 3-26 fb and 6-33 fb, respectively.", optnote="WOS:001090914900001", optnote="exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5838), last updated on Mon, 18 Dec 2023 08:34:58 +0000", issn="1029-8479", doi="10.1007/JHEP10(2023)009", opturl="https://arxiv.org/abs/2307.11120", opturl="https://doi.org/10.1007/JHEP10(2023)009", language="English" }