CMS-PAS-SMP-15-008

CMS-PAS-SMP-15-008
Measurements of the $\mathrm{ pp \to W^{\pm} \gamma \gamma }$ and $\mathrm{ pp \to Z \gamma \gamma }$ cross sections and limits on dimension-8 effective anomalous gauge couplings at $\sqrt{s} =$ 8 TeV
CMS Collaboration
February 2016

Abstract: We present measurements of the cross sections of the $\mathrm{ pp \to W ^{\pm} \gamma \gamma }$ and $\mathrm{ pp \to Z \gamma\gamma }$ final states in the channels where the W boson decays to muons and Z boson decays to electrons or muons. The measurement uses 19.4 fb $^{-1}$ of 8 TeV data collected with the CMS experiment in 2012. We observe the signal for $\mathrm{ W^{\pm} \gamma \gamma }$ with a significance of 2.4 $\sigma$ and we observe the $\mathrm{ Z \gamma \gamma }$ signal with a significance of 5.9 $\sigma$ . Upper limits are placed on anomalous quartic gauge couplings using the $\mathrm{ W^{\pm} \gamma \gamma }$ final state, with particular sensitivity to the $f_{\mathrm{T}, 0}$ coupling. The observed 95% confidence level limit on the $f_{\mathrm{T}, 0}$ coupling is $-37.5 < \frac{f_{\mathrm{T}, 0}}{\Lambda^4} < 38.1$ .
Links: CDS record (PDF) ; inSPIRE record ; CADI line (restricted) ; These preliminary results are superseded in this paper, JHEP 10 (2017) 072. The superseded preliminary plots can be found here.

CMS Publications