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 (Formula presented.) , 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 (Formula presented.) , 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 (Formula presented.) for 10 GeV (Formula presented.) 62 GeV. Limits are also presented for Higgs boson-like scalars (H) for (Formula presented.) 125 GeV, and for a (Formula presented.) decaying to three photons via (Formula presented.). Additionally, the observed limit on the branching ratio of the Z boson decay to three photons is found to be BR (Formula presented.) , a result five times stronger than the previous result from LEP. © 2016, CERN for the benefit of the ATLAS collaboration.
Search for new phenomena in events with at least three photons collected in pp collisions at √s = 8 TeV with the ATLAS detector / Aad, G., Aloisio, A., Alviggi, M., Canale, V., DELLA VOLPE, D., Merola, L., Conventi, F., DELLA PIETRA, M., Giordano, R., Perrella, S., Rossi, E., Cirotto, F., SANCHEZ PINEDA, A.R., Carlino, G., DE ASMUNDIS, R., DI DONATO, C., Doria, A., Iengo, P., Izzo, V., Sekhniaidze, G., et al.. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - 76:4(2016). [10.1140/epjc/s10052-016-4034-8]
Search for new phenomena in events with at least three photons collected in pp collisions at √s = 8 TeV with the ATLAS detector
ALOISIO, ALBERTO;ALVIGGI, MARIAGRAZIA;CANALE, VINCENZO;DELLA VOLPE, DOMENICO;MEROLA, LEONARDO;CONVENTI, FRANCESCO;DELLA PIETRA, MASSIMO;GIORDANO, RAFFAELE;PERRELLA, SABRINA;ROSSI, ELVIRA;CIROTTO, FRANCESCO;SANCHEZ PINEDA, ARTURO RODOLFO;CARLINO, GIANPAOLO;DE ASMUNDIS, Riccardo;DI DONATO, CAMILLA;IENGO, PAOLO;IZZO, VINCENZO;
2016
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 (Formula presented.) , 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 (Formula presented.) , 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 (Formula presented.) for 10 GeV (Formula presented.) 62 GeV. Limits are also presented for Higgs boson-like scalars (H) for (Formula presented.) 125 GeV, and for a (Formula presented.) decaying to three photons via (Formula presented.). Additionally, the observed limit on the branching ratio of the Z boson decay to three photons is found to be BR (Formula presented.) , a result five times stronger than the previous result from LEP. © 2016, CERN for the benefit of the ATLAS collaboration.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
