$\gamma\gamma$ and $\gamma p$ measurements with forward proton taggers in CMS+TOTEM

Abstract

The CMS+TOTEM Precision Proton Spectrometer operated for the first time in 2016, collecting data during $pp$ collisions at $\sqrt{s} = 13$ TeV at the CERN Large Hadron Collider. Procedures for the detector alignment, optics corrections, and background estimations were developed, and applied to an analysis of the process $pp \rightarrow p \mu^{+}\mu^{-} p^{(*)}$ with dimuon masses larger than 110 GeV. A total of 12 candidate events are observed, corresponding to an excess of $>4\sigma$ over the background prediction. This constitutes the first evidence for this process at such masses, and demonstrates the good performance of CT-PPS.