Measurement of exclusive Upsilon photoproduction in pPb collisions at $\sqrt{s_{NN}}=5.02$ TeV with the CMS

The exclusive photoproduction of $\mathrm{{\rm Y}}$(1S), $\mathrm{{\rm Y}}$(2S) and $\mathrm{{\rm Y}}$(3S) mesons is studied in their leptonic (${\mu }^{+}{\mu }^{-}$) decay modes, in ultraperipheral pPb collisions at $\sqrt{s_{NN}}=5.02$ TeV. The data was recorded by the CMS experiment corresponding to an integrated luminosity of $32.6$ nb${}^{-1}$. The differential cross-section for $\mathrm{{\rm Y}}$(n) states (n=1,2,3), has been measured as a function of transverse momentum squared $p_T^2$, and rapidity $y$. The $\mathrm{{\rm Y}}$(1S) photoproduction cross-section is extracted in the region $\mathrm{\mid }y\mathrm{\mid }<2.2$ as a function of the photon-proton centre-of-mass energies $W_{\gamma p}$, in the range $91<W_{\gamma p}<826$ GeV. The measurements are compared to theoretical predictions and to previous measurements.