Search for rare decays of Z and Higgs bosons to J / ψ and a photon in proton-proton collisions at √s = 13 TeV
Abstract
A search is presented for decays of Z and Higgs bosons to a J/ψ meson and a photon, with the subsequent decay of the J/ψ to μ+μ−. The analysis uses data from proton-proton collisions with an integrated luminosity of 35.9fb−1 at s√=13TeV collected with the CMS detector at the LHC. The observed limit on the Z→J/ψγ decay branching fraction, assuming that the J/ψ meson is produced unpolarized, is 1.4×10−6 at 95% confidence level, which corresponds to a rate higher than expected in the standard model by a factor of 15. For extreme-polarization scenarios, the observed limit changes from −13.6 to +8.6% with respect to the unpolarized scenario. The observed upper limit on the branching fraction for H→J/ψγ where the J/ψ meson is assumed to be transversely polarized is 7.6×10−4, a factor of 260 larger than the standard model prediction. The results for the Higgs boson are combined with previous data from proton-proton collisions at s√=8TeV to produce an observed upper limit on the branching fraction for H→J/ψγ that is a factor of 220 larger than the standard model value. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000324003Publication status
publishedExternal links
Journal / series
The European Physical Journal CVolume
Pages / Article No.
Publisher
SpringerOrganisational unit
03593 - Dissertori, Günther / Dissertori, Günther
03904 - Wallny, Rainer / Wallny, Rainer
08803 - Grab, Christoph (Tit.Prof.)
09631 - Shchutska, Lesya (ehemalig) / Shchutska, Lesya (former)
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