A search for the decays of the Higgs and Z bosons to J/ψγ and γ(nS)γ (n=1,2,3) is performed with pp collision data samples corresponding to integrated luminosities of up to 20.3 fb-1 collected at s=8 TeV with the ATLAS detector at the CERN Large Hadron Collider. No significant excess of events is observed above expected backgrounds and 95% C.L. upper limits are placed on the branching fractions. In the J/ψγ final state the limits are 1.5×10-3 and 2.6×10-6 for the Higgs and Z boson decays, respectively, while in the γ(1S,2S,3S)γ final states the limits are (1.3,1.9,1.3)×10-3 and (3.4,6.5,5.4)×10-6, respectively.

Aad, G., Abbott, B., Abdallah, J., Abdel Khalek, S., Abdinov, O., Aben, R., et al. (2015). Search for Higgs and Z Boson Decays to J/psi gamma and Upsilon(nS)gamma with the ATLAS Detector. PHYSICAL REVIEW LETTERS, 114(12), 1-19 [10.1103/PhysRevLett.114.121801].

Search for Higgs and Z Boson Decays to J/psi gamma and Upsilon(nS)gamma with the ATLAS Detector

F. Ceradini;B. Di Micco;R. Di Nardo;D. Orestano;F. Petrucci;D. Puddu;