Feasibility study of pion and kaon structure via the Sullivan process at the EicC

The Electron-Ion Collider in China (EicC) provides an excellent opportunity to explore the internal structure of pions and kaons via the Sullivan process in deep-inelastic scattering. In this study, we present detailed projections for the pion and kaon structure functions F 2 π and F 2 K , respectively, at the EicC, with a focus on both statistical and systematic uncertainties. Leveraging EicC’s high luminosity and broad kinematic coverage, the accessible kinematic region is extended beyond previous measurements. The projected statistical uncertainties for F 2 π and F 2 K are below 5% and 8%, respectively, across most kinematic bins. Systematic uncertainties arising from detector effects have been carefully evaluated. These results significantly enhance the precision of meson structure function measurements and provide important constraints on theoretical models of meson parton distributions. Moreover, this study bridges the gap between fixed-target and collider-era measurements, highlighting the pivotal role of EicC in advancing our understanding of hadronic structure.