Exclusive Production of Vector Mesons at the LHCb

Studies of the central exclusive production (CEP) of vector mesons in \(pp\) collisions at the LHCb are reported. A search is performed for the CEP of charmonium pairs using data corresponding to an integrated luminosity of 3 fb\(^{-1}\) collected at centre-of-mass energies of 7 and 8 TeV. Pairs of \(J/\psi \,J/\psi \) and \(J/\psi \psi (2S)\) are observed in the absence of any other activity inside the LHCb acceptance and the measured cross sections are consistent with theoretical expectations. A study of CEP of \({\mit \Upsilon }(nS)\) states based on the same data is presented. The \({\mit \Upsilon }(1S)\) cross section is measured as a function of rapidity and is found to be in good agreement with the Standard Model predictions. The CEP of \(J/\psi \) and \(\psi (2S)\) mesons is measured at \(\sqrt {s}=13\) TeV and backgrounds are significantly reduced compared to previous measurements through the use of forward shower counters.