Hayrapetyan, A.Tumasyan, A.Adam, W.Andrejkovic, J. W.Bergauer, T.Chatterjee, S.Nuernberg, A.2025-03-222025-03-2220250031-90071079-7114https://doi.org/10.1103/PhysRevLett.134.041801De Souza Lemos, Dener/0000-0003-1982-8978; Ribeiro Lopes, Beatriz/0000-0003-0823-447X; Figueiredo, Diego/0000-0003-2514-6930; Richards, Alexander/0000-0002-9265-3679; Pereira, Miguel/0000-0003-4296-7028; Phor, Saumya/0000-0001-7842-9518; Hajahmad, Vael/0000-0003-1491-0446; Pérez Prada, Maximilian/0000-0002-2831-463X; Consuegra Roiguez, Sana/0000-0002-1383-1837; Christoforou, Konstantinos/0000-0003-2205-1100; Erice Cid, Carlos Francisco/0000-0002-6469-3200; Palencia Cortezon, Jose Enrique/0000-0001-8264-0287; Thachayath Sugunan, Aravind/0000-0001-6545-0350; Faccioli, Pietro/0000-0003-1849-6692; Noll, Dennis Daniel Nick/0000-0002-0176-2360; Jaramillo Gallego, Johny/0000-0003-3885-6608; Ruiz, Jose/0000-0002-3306-0363; Giacomo, Bolini/0000-0001-5490-605X; Agicevic, Marko/0000-0003-1967-6783; Fernández Ramos, Juan Pablo/0000-0002-0122-313X; Eimanis, Karlis/0000-0003-0972-5641; Painesis, Haris/0000-0001-5061-7031; Wilson, Jonathan/0000-0002-5672-7394A search is presented for an extended Higgs sector with two new particles, X and., in the process X ->phi phi ->(gamma gamma)(gamma gamma).Novel neural networks classify events with diphotons that are merged and determine the diphoton masses. The search uses LHC proton-proton collision data at root s = 13 TeV collected with the CMS detector, corresponding to an integrated luminosity of 138 fb(-1). No evidence of such resonances is seen. Upper limits are set on the production cross section for m(X) between 300 and 3000 GeV and m.=m(X) between 0.5% and 2.5%, representing the most sensitive search in this channel.eninfo:eu-repo/semantics/openAccessArticle10.1103/PhysRevLett.134.0418012-s2.0-85217077353