An indirect probe of higgsino world at the CEPC

The higgsino world is one of the popular natural SUSY scenarios, in which $\mathrm{\mid }\mu \mathrm{\mid }\ll M_{gauginos}\ll M_{scalars}$. As such, searching for light degenerate higgsinos becomes an essential task of testing naturalness in supersymmetry (SUSY). In this work, we study the indirect effects of light higgsinos in the process $e^{+}{e}^{-}\to W^{+}{W}^{-}$ at future Higgs factories, such as Circular Electron Positron Collider (CEPC) in China. we find that the higgsino mass parameter $\mu \lesssim 210$ GeV favored by naturalness can be covered if the accuracy of the measurement of $W^{+}{W}^{-}$ production can reach 0.1% at 240 GeV CEPC.