Recent results on Central Exclusive Production with the STAR detector

Abstract

We present results on the Central Exclusive Production of charged particle pairs $h^{+}h^{-}$ ($h = \pi, K, p$), $pp\to p^\prime+h^{+}h^{-}+p^\prime$, obtained with the STAR experiment at RHIC in proton-proton collisions at a center-of-mass energy of $\sqrt{s} = 200$ GeV. All final-state particles were reconstructed, including forward-scattered protons detected in the Roman Pot system. As a result, the Double Pomeron Exchange (DPE) events were selected and the non-exclusive backgrounds were efficiently rejected. Differential fiducial cross sections were measured as functions of observables related to the central hadronic final state and to the forward-scattered protons. The measured cross sections were compared to phenomenological model predictions based on the DPE. We also present preliminary results on the measurement of the same physics process at higher collision energy $\sqrt{s} = 510$ GeV. The data demonstrate features similar to those observed at $\sqrt{s} = 200$ GeV.