ePIC will be a general-purpose detector designed to enalbe the entire physics program of the Electron-Ion Collider (EIC) at BNL, USA. Several key physics measurements depend on efficient Particle Identification (PID). The PID system of ePIC covers a wide pseudorapidity (−3.3 < 𝜂 < 3.5) and momentum range. Several technologies have been identified to serve such a purpose.
In the forward region (1.5 < 𝜂 < 3.5) a Dual Ring Imaging Cerenkov detector (dRICH) will be employed to provide efficient and continuous hadron PID from 3 GeV/c to 50 GeV/c and to support the electromagnetic calorimeter by pion rejection in the lower momentum region. The dRICH comprises two different radiators, aerogel and gas (𝐶2𝐹6), to cover the entire momentum range. SiPM based photosensors are placed in six spherical sectors to detect Cherenkov photons which are focused by six corresponding spherical mirrors. Here we introduce the dRICH detector and discuss results from simulation studies, with a special focus on the separation power for pions and kaons and its dependency on the particle momentum and pseudorapidity.