Search for new phenomena in events with at least three photons collected in pp collisions at √s = 8 TeV with the ATLAS detector
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 d...
Guardado en:
| Publicado: |
2016
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14346044_v76_n4_p_Aad http://hdl.handle.net/20.500.12110/paper_14346044_v76_n4_p_Aad |
| Aporte de: |
| Sumario: | 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 → γ γ) 2 < 10 −3 σSM 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. © CERN for the benefit of the ATLAS collaboration 2016. |
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