TY - JOUR AU - ATLAS Collaboration (Aad, G. et al AU - Aparisi Pozo, J. A. AU - Bailey, A. J. AU - Cabrera Urban, S. AU - Castillo, F. L. AU - Castillo Gimenez, V. AU - Costa, M. J. AU - Escobar, C. AU - Estrada Pastor, O. AU - Ferrer, A. AU - Fiorini, L. AU - Fullana Torregrosa, E. AU - Fuster, J. AU - Garcia, C. AU - Garcia Navarro, J. E. AU - Gonzalez de la Hoz, S. AU - Gonzalvo Rodriguez, G. R. AU - Guerrero Rojas, J. G. R. AU - Higon-Rodriguez, E. AU - Lacasta, C. AU - Lozano Bahilo, J. J. AU - Madaffari, D. AU - Mamuzic, J. AU - Marti-Garcia, S. AU - Martinez Agullo, P. AU - Miralles Lopez, M. AU - Mitsou, V. A. AU - Moreno Llacer, M. AU - Poveda, J. AU - Rodriguez Bosca, S. AU - Ruiz-Martinez, A. AU - Salt, J. AU - Santra, A. AU - Sayago Galvan, I. AU - Soldevila, U. AU - Sanchez, J. AU - Valero, A. AU - Valls Ferrer, J. A. AU - Vos, M. PY - 2020 DA - 2020// TI - CP Properties of Higgs Boson Interactions with Top Quarks in the (tt)over-barH and tH Processes Using H -> gamma gamma with the ATLAS Detector T2 - Phys. Rev. Lett. JO - Physical Review Letters SP - 061802 EP - 21pp VL - 125 IS - 6 PB - Amer Physical Soc AB - A study of the charge conjugation and parity (CP) properties of the interaction between the Higgs boson and top quarks is presented. Higgs bosons are identified via the diphoton decay channel (H -> gamma gamma), and their production in association with a top quark pair ((tt) over barH) or single top quark (tH) is studied. The analysis uses 139 fb(-1) of proton-proton collision data recorded at a center-of-mass energy off root s= 13 TeV with the ATLAS detector at the Large Hadron Collider. Assuming a CP-even coupling, the (tt) over barH process is observed with a significance of 5.2 standard deviations. The measured cross section times H -> gamma gamma branching ratio is 1.64(-0.36)(+0.38)(stat)(-0.14)(+0.17) (sys) fb, and the measured rate for (tt) over barH is 1.43(-0.31)(+0.33) (stat)(-0.15)(+0.21) (sys) times the Standard Model expectation. The tH production process is not observed and an upper limit on its rate of 12 times the Standard Model expectation is set. A CP-mixing angle greater (less) than 43 (-43)degrees is excluded at 95% confidence level. SN - 0031-9007 UR - https://arxiv.org/abs/2004.04545 UR - https://doi.org/10.1103/PhysRevLett.125.061802 DO - 10.1103/PhysRevLett.125.061802 LA - English N1 - WOS:000555785600003 ID - ATLASCollaborationAad_etal2020 ER -