Optimization of tracker configuration for the CEPC

We investigate the tracker configuration optimization for Circular Electron Position Collider (CEPC), a proposed Higgs and $Z$ factory. Fixing construction cost comparable to that of baseline detector design considering benchmark channels ($Z\rightarrow f\bar{f}$, $WW$ fusion with $H\rightarrow $ZH\rightarrow\nu\bar{\nu}f\bar{f}$, $t\bar{t}\rightarrow b\bar{b}\mu\nu_\mu ud$) various operating modes CEPC, we obtain optimal radius provides best average resolution track momentum or jet energy. The radii range from 1.59\,m 1.73\,m energy 1.82\,m 1.97\,m, depending on channels. Compared jets, tracks prefer smaller longer length because degrades more significantly than in forward region. channel $Z$-pole prefers compared other final state particles at have distribution. also analyze scaling behavior floating observe weak dependence.