Search for new phenomena in events with at least three photons collected in pp collisions at √s = 8 TeV with the ATLAS detector

0470746 - FZÚ 2017 RIV US eng J - Journal Article
Aad, G. - Abbott, B. - Abdallah, J. - Chudoba, Jiří - Havránek, Miroslav - Hejbal, Jiří - Jakoubek, Tomáš - Kepka, Oldřich - Kupčo, Alexander - Kůs, Vlastimil - Lokajíček, Miloš - Lysák, Roman - Marčišovský, Michal - Mikeštíková, Marcela - Němeček, Stanislav - Penc, Ondřej - Šícho, Petr - Staroba, Pavel - Svatoš, Michal - Taševský, Marek - Vrba, Václav … Total 2873 authors
Search for new phenomena in events with at least three photons collected in pp collisions at √s = 8 TeV with the ATLAS detector.
European Physical Journal C. Roč. 76, č. 4 (2016), s. 1-37, č. článku 210. ISSN 1434-6044. E-ISSN 1434-6052
Institutional support: RVO:68378271
Keywords : CERN LHC Coll * CERN LEP Stor * mass spectrum * neutralino * mass * flavor * data analysis method * experimental results * 8000 GeV-cms * ATLAS
Subject RIV: BF - Elementary Particles and High Energy Physics
Impact factor: 5.297, year: 2016

Results of a search for new phenomena in events with at least three photons are reported. Data from proton–proton collisions at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3 fb−1 , were collected with the ATLAS detector at the LHC. The observed data are well described by the Standard Model. Limits at the 95 % confidence level on new phenomena are presented based on the rate of events in an inclusive signal region and a restricted signal region targeting the rare decay Z→3γ , as well as di-photon and tri-photon resonance searches. For a Standard Model Higgs boson decaying to four photons via a pair of intermediate pseudoscalar particles (a), limits are found to be σ× BR (h→aa)× BR (a→γγ)2<10−3σSM for 10 GeV <ma< 62 GeV. Limits are also presented for Higgs boson-like scalars (H) for mH> 125 GeV, and for a Z′ decaying to three photons via Z′→a+γ→3γ . Additionally, the observed limit on the branching ratio of the Z boson decay to three photons is found to be BR (Z→3γ)<2.2×10−6 , a result five times stronger than the previous result from LEP.

Permanent Link: http://hdl.handle.net/11104/0268317