Simulation Comparison for the mSTS Geometry based on ROOT Primitive Solids and Tessellated Solids

The Compressed Baryonic Matter (CBM) is a heavy-ion experiment, currently under construction, at the Facility for Anti-Proton and Ion Research (FAIR) in Darmstadt, Germany. It aims to explore the QCD phase diagram at high baryon density (µ B ) using the SIS-100 accelerator at FAIR. The Silicon Tracking System (STS) is the main detector for tracking and momentum determination. A scaled-down prototype of various detector systems, including mini STS (mSTS), is being meticulously tested in the mini CBM (mCBM) experiment at the existing SIS-18 accelerator at GSI, Helmholtzzentrum für Schwerionenforschung in Darmstadt. This experiment seeks to comprehensively assess both hardware and software components, ensuring their efficacy in online readout, processing, and analyzing the intricate topological data generated by real events detected by the detector subsystems. The recent development provides a facility to convert the Computer-Aided Design (CAD) based geometry model to Geometry Description Markup Language (GDML), an XML-based format. The representation of the solids extracted from a CAD toolkit typically consists of triangular or quadrilateral facets. The GDML file is then used in ROOT and GEANT4 using TGDMLParser and G4GDMLParser respectively to read the information of geometry volumes and to create different volume assemblies to prepare the simulation geometry to be used in the simulation. This report presents a comparative analysis of simulation studies using two distinct representations of the mSTS geometry: one employing simplified primitive solids and the other utilizing tessellated solid-based geometry, including the run-time, secondary particle production, and z-vertex of the secondary particles.