Allbrooke, B M M, Asquith, L, Cerri, A, Chavez Barajas, C A, De Santo, A, Salvatore, F, Santoyo Castillo, I, Suruliz, K, Sutton, M R, Vivarelli, I and The ATLAS Collaboration, (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). p. 210. ISSN 1434-6044
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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, 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.
Item Type: | Article |
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Schools and Departments: | School of Mathematical and Physical Sciences > Physics and Astronomy |
Research Centres and Groups: | Experimental Particle Physics Research Group |
Subjects: | Q Science > QC Physics |
Depositing User: | Richard Chambers |
Date Deposited: | 15 Feb 2017 09:20 |
Last Modified: | 07 Mar 2017 11:46 |
URI: | http://srodev.sussex.ac.uk/id/eprint/66753 |
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📧 Request an updateProject Name | Sussex Project Number | Funder | Funder Ref |
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STFC Consolidated Grant Supplement | G1316 | STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCIL | ST/M000753/1 |