Exclusive production of $W$ pairs in CMS
We report the results on the search for exclusive production of $W$ pairs in the LHC with data collected by the Compact Muon Solenoid detector in proton-proton collisions at $\sqrt{s}$ = 7 TeV. The analysis comprises the two-photon production of a $W$ pairs, ${pp\to p\,W^{+}W^{-}\,p\to p\,\nu e^{\pm}\nu\mu^{\mp}\,p}$. Two events are observed in data for $p_{\textrm{\footnotesize T}}(\ell)>$ 4 GeV, $|\eta(\ell)|<$ 2.4 and $m(\mu^{\pm}e^{\mp})>$ 20 GeV, in agreement with the standard model prediction of 2.2 $\pm$ 0.4 signal events with 0.84 $\pm$ 0.15 background events. Moreover, a study of the tail of the lepton pair transverse momentum distribution is performed to search for an evidence of anomalous quartic gauge couplings in the $\gamma\gamma\to W^{+}W^{-}$ vertex. As no events are observed in data, it results in a model-independent upper limits for the anomalous quartic gauge couplings $a^{W}_{0,C}/\Lambda^{2}$, which are of the order of 10$^{-4}$.