Central Tracking Chamber, CDC

The efficient reconstruction of charged particle tracks and precise determination of their momenta is an essential ingredient to virtually all of the measurements planned for the Belle experiment. Specifically, the physics goals of the experiment require a momentum resolution of $\sigma_{p_t} /p_t \sim 0.5 \% \sqrt{1 + p^2_t}$ ($p_t$ in GeV/c) for all charged particles with $p_t \ge$ 100 MeV/c in the polar angle region of $17^o \le \theta \le 150^o$. In addition, the charged particle tracking system is expected to provide important information for the trigger system and particle identification information in the form of precise $dE/dx$ measurements for charged particles [4].