Measurements of the $pp\to\mathrm{W}^{\pm}\gamma\gamma$ and $pp\to\mathrm{Z}\gamma\gamma$ cross sections and Limits on Dimension-8 Effective Anomalous Gauge Couplings at $\sqrt{s} = 8~\mathrm{TeV}$

We present measurements of the cross sections of the $pp\to\,$W$^{\pm}\gamma\gamma\,$ and $pp\to\,$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 $19.4~\mathrm{fb}^{-1}$ of $8$ TeV data collected with the CMS experiment in 2012. We observe the signal for W$^{\pm}\gamma\gamma\,$ with a significance of $2.4 \sigma$ and we observe the Z$\gamma\gamma\,$ signal with a significance of $5.9 \sigma$. Upper limits are placed on anomalous quartic gauge couplings using the 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 $-37.5 < \frac{f_{\mathrm{T}, 0}}{\Lambda^4} < 38.1$.