Measurement of the Central Exclusive Production of pion pairs using tagged forward protons at the STAR detector at RHIC

Abstract

We present preliminary measurement of the invariant mass spectrum of the two oppositely charged pions produced in the process pp → pπ+π−p (Central Exclusive Production), obtained with the STAR detector at RHIC at √(s) = 200 GeV. The Roman Pots were used to tag forward protons and the invariant mass of the pion pair was obtained using tracks reconstructed in the STAR Time Projection Chamber (TPC). The non-exclusive background estimated from events with like-sign track pairs is small, thus proof of principle of this type of the measurement at small momentum transfer to proton is established. Plans for the future are also discussed.