CMS-PAS-EXO-20-001

CMS-PAS-EXO-20-001
Search for W$ \gamma $ resonances using hadronic decays of Lorentz-boosted W bosons in proton-proton collisions at $\sqrt{s} = $ 13 TeV
CMS Collaboration
March 2021

Abstract: A search for W$ \gamma $ resonances in the mass range between 700 and 6000 GeV is presented. The W boson is reconstructed via its hadronic decay, with the final-state products forming a single, large-radius jet, owing to a large Lorentz boost of the W boson. The search is based on proton-proton collision data at $\sqrt{s} = $ 13 TeV, collected with the CMS detector in 2016-2018, corresponding to an integrated luminosity of 137 fb$^{-1}$. The W$ \gamma $ invariant mass spectrum is parameterized with a smoothly falling background function and examined for the presence of resonance-like signals. No significant excesses above the predicted background are observed. Model-specific limits at 95% confidence level on the production cross section times branching fraction to the W$ \gamma $ channel are set for narrow resonances and for resonances with an intrinsic width equal to 5% of their mass, for spin-0 and spin-1 hypotheses, ranging between 0.11 and 35 fb. These are the most restrictive limits to date on the existence of such resonances. Model-independent limits on the production cross section times branching fraction to the W$ \gamma $ channel times signal acceptance are also set for minimum W$ \gamma $ mass thresholds between 1500 and 8000 GeV, allowing for testing more general models predicting production of a photon in association with a jet consistent with a hadronic W or Z boson decay.
Links: CDS record (PDF) ; inSPIRE record ; CADI line (restricted) ; These preliminary results are superseded in this paper, Submitted to PLB. The superseded preliminary plots can be found here.

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