Study of exclusive two-photon production of $W^+W^-$ in $pp$ collisions at $\sqrt{s} = 7$ TeV and constraints on anomalous quartic gauge couplings

A search for exclusive or quasi-exclusive W(+)W(−) production by photon-photon interactions, pp → p((*))W(+)W(−)p((*)), at TeV is reported using data collected by the CMS detector with an integrated luminosity of 5.05 fb(−1). Events are selected by requiring a μ (±)e(∓) vertex with no additional associated charged tracks and dilepton transverse momentum p (T)(μ (±)e(∓)) > 30 GeV. Two events passing all selection requirements are observed in the data, compared to a standard model expectation of 2.2 ± 0.4 signal events with 0.84 ± 0.15 background. The tail of the dilepton p (T) distribution is studied for deviations from the standard model. No events are observed with p (T) > 100 GeV. Model-independent upper limits are computed and compared to predictions involving anomalous quartic gauge couplings. The limits on the parameters with a dipole form factor and an energy cutoff Λ(cutoff) = 500 GeV are of the order of 10(−4).