Search for $WW$ $\gamma$ and $WZ$ $\gamma$ production and constraints on anomalous quartic gauge couplings in $pp$ collisions at $\sqrt{s}=8\text{ }\text{ }\mathrm{TeV}$

Abstract

A search for $WV$ $\gamma$ triple vector boson production is presented based on events containing a $W$ boson decaying to a muon or an electron and a neutrino, a second $V$ ($W$ or $Z$) boson, and a photon. The data correspond to an integrated luminosity of $19.3\text{ }\text{ }{\mathrm{fb}}^{$-${}1}$ collected in 2012 with the CMS detector at the LHC in $pp$ collisions at $\sqrt{s}=8\text{ }\text{ }\mathrm{TeV}$. An upper limit of 311 fb on the cross section for the $WV$ $\gamma$ production process is obtained at 95% confidence level for photons with a transverse energy above 30 GeV and with an absolute value of pseudorapidity of less than 1.44. This limit is approximately a factor of 3.4 larger than the standard model predictions that are based on next-to-leading order QCD calculations. Since no evidence of anomalous $WW$$\gamma$ or $WWZ$ $\gamma$ quartic gauge boson couplings is found, this paper presents the first experimental limits on the dimension-eight parameter ${f}_{T,0}$ and the $CP$-conserving $WWZ$ $\gamma$ parameters ${$\kappa${}}_{0}^{W}$ and ${$\kappa${}}_{C}^{W}$. Limits are also obtained for the $WW$ $\gamma$$\gamma$ parameters ${a}_{0}^{W}$ and ${a}_{C}^{W}$.