TY - JOUR AU - ATLAS Collaboration (Aad, G. et al AU - Akiot, A. AU - Amos, K. R. AU - Aparisi Pozo, J. A. AU - Bailey, A. J. AU - Bouchhar, N. AU - Cabrera Urban, S. AU - Cantero, J. AU - Cardillo, F. AU - Castillo Gimenez, V. AU - Chitishvili, M. AU - Costa, M. J. AU - Didenko AU - Escobar, C. AU - Fiorini, L. AU - Fullana Torregrosa, E. AU - Fuster, J. AU - Garcia, C. AU - Garcia Navarro, J. E. AU - Gomez Delegido, A. J. AU - Gonzalez de la Hoz, S. AU - Gonzalvo Rodriguez, G. R. AU - Guerrero Rojas, J. G. R. AU - Lacasta, C. AU - Marti-Garcia, S. AU - Martinez Agullo, P. AU - Miralles Lopez, M. AU - Mitsou, V. A. AU - Monsonis Romero, L. AU - Moreno Llacer, M. AU - Munoz Perez, D. AU - Navarro-Gonzalez, J. AU - Poveda, J. AU - Prades Ibañez, A. AU - Rubio Jimenez, A. AU - Ruiz-Martinez, A. AU - Sabatini, P. AU - Salt, J. AU - Sanchez Sebastian, V. AU - Sayago Galvan, I. AU - Senthilkumar, V. AU - Soldevila, U. AU - Sanchez, J. AU - Torro Pastor, E. AU - Valero, A. AU - Valls Ferrer, J. A. AU - Varriale, L. AU - Villaplana Perez, M. AU - Vos, M. PY - 2023 DA - 2023// TI - 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 τ-leptons with the ATLAS detector T2 - J. High Energy Phys. JO - Journal of High Energy Physics SP - 009 EP - 46pp VL - 10 IS - 10 PB - Springer KW - Hadron-Hadron Scattering AB - 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. SN - 1029-8479 UR - https://arxiv.org/abs/2307.11120 UR - https://doi.org/10.1007/JHEP10(2023)009 DO - 10.1007/JHEP10(2023)009 LA - English N1 - WOS:001090914900001 ID - ATLASCollaborationAad_etal2023 ER -