Simulation studies for the layout of the vertex and tracking regions of the CLIC detectors

The physics requirements and beam parameters of the proposed CLIC concept for a compact linear electron-positron collider with a centre-of-mass energy of up to 3 TeV pose challenging demands for the design of the vertex and tracking-detector regions. The physics program of CLIC requires an excellent track-momentum resolution and efficient tagging of decays involving heavy quarks or tau-leptons by reconstructing their displaced vertices. The layer placement as well as the temporal and spatial readout granularity are severely constrained by the high rates of beam-induced background events in the vicinity of the interaction region. We present fast simulation studies for various detector layouts. The main detector parameters and their interplay are investigated: Momentum and impact-parameter resolutions, occupancies and background rejection. These parameters are determined as a function of the number and placement of detector layers, their single-point resolutions and the material budget.