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

Barton, Adam Edward and Beattie, Michael and Borissov, Guennadi and Bouhova-Thacker, Evelina Vassileva and Dearnaley, William and Fox, Harald and Grimm, Kathryn Ann Tschann and Henderson, Robert Charles William and Hughes, Gareth and Jones, Roger William Lewis and Kartvelishvili, Vakhtang and Long, Robin Eamonn and Love, Peter Allan and Maddocks, Harvey and Skinner, Malcolm and Smizanska, Maria and Walder, James William and Wharton, Andy (2016) 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: Particles and Fields, 76 (4). ISSN 1434-6044

[img]
Preview
PDF (art%3A10.1140%2Fepjc%2Fs10052-016-4034-8)
art_3A10.1140_2Fepjc_2Fs10052_016_4034_8.pdf - Published Version
Available under License Creative Commons Attribution.

Download (2MB)

Abstract

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−1−1, 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→3γZ→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<10−3σSMσ× BR (h→aa)× BR (a→γγ)2<10−3σSM for 10 GeV <ma<<ma< 62 GeV. Limits are also presented for Higgs boson-like scalars (H) for mH>mH> 125 GeV, and for a Z′Z′ decaying to three photons via Z′→a+γ→3γZ′→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(Z→3γ)<2.2×10−6, a result five times stronger than the previous result from LEP.

Item Type: Journal Article
Journal or Publication Title: European Physical Journal C: Particles and Fields
Uncontrolled Keywords: /dk/atira/pure/subjectarea/asjc/2200/2201
Subjects:
Departments: Faculty of Science and Technology > Physics
ID Code: 79387
Deposited By: ep_importer_pure
Deposited On: 06 May 2016 14:38
Refereed?: Yes
Published?: Published
Last Modified: 14 Oct 2019 08:25
URI: https://eprints.lancs.ac.uk/id/eprint/79387

Actions (login required)

View Item View Item