Search for Higgs boson decays to beyond-the-Standard-Model light bosons in four-lepton events with the ATLAS detector at $\sqrt{s}=13$ TeV : arXiv

Author(s): Aaboud, M; Aad, G; Abbott, B; Abdinov, O; Abeloos, B; Abidi, SH; AbouZeid, OS; Abraham, NL; Abramowicz, H; Abreu, H; Abreu, R; Abulaiti, Y; Acharya, BS; Adachi, S; Adamczyk, L; Adelman, J; Adersberger, M; Adye, T; Affolder, AA; Afik, Y; Agatonovic-Jovin, T; Agheorghiesei, C; Aguilar-Saavedra, JA; Ahlen, SP; Ahmadov, F; Aielli, G; Akatsuka, S; Akerstedt, H; Akesson, TPA; Akilli, E; Akimov, AV; Alberghi, GL; Albert, J; Albicocco, P; Alconada Verzini, MJ; Alderweireldt, SC; Aleksa, M; Aleksandrov, IN; Alexa, C; Alexander, G; Alexopoulos, T; Alhroob, M; Ali, B; Aliev, M; Alimonti, G; Alison, J; Alkire, SP; Allbrooke, BMM; Allen, BW; Allport, PP; Aloisio, A; Alonso, A; Alonso, F; Alpigiani, C; Alshehri, AA; Alstaty, MI; Alvarez Gonzalez, B; Alvarez Piqueras, D; Alviggi, MG; Amadio, BT; Amaral Coutinho, Y; Amelung, C; Amidei, D; Amor Dos Santos, SP; Amoroso, S; Amundsen, G; Anastopoulos, C; Ancu, LS; Andari, N; Andeen, T; Anders, CF; Anders, JK; Anderson, KJ; Andreazza, A; Andrei, V; Angelidakis, S; Angelozzi, I; Angerami, A; Anisenkov, AV; Anjos, N; Annovi, A; Antel, C; Antonelli, M; Antonov, A; Antrim, DJ | Abstract: © 2018, The Author(s). A search is conducted for a beyond-the-Standard-Model boson using events where a Higgs boson with mass 125 GeV decays to four leptons (l = e or μ). This decay is presumed to occur via an intermediate state which contains one or two on-shell, promptly decaying bosons: H → ZX/XX → 4l, where X is a new vector boson Zdor pseudoscalar a with mass between 1 and 60 GeV. The search uses pp collision data collected with the ATLAS detector at the LHC with an integrated luminosity of 36.1 fb−1at a centre-of-mass energy s=13 TeV. No significant excess of events above Standard Model background predictions is observed; therefore, upper limits at 95% confidence level are set on modelindependent fiducial cross-sections, and on the Higgs boson decay branching ratios to vector and pseudoscalar bosons in two benchmark models.[Figure not available: see fulltext.].