Heavy quark mass effects in charged-current deep-inelastic scattering at approximate NNLO in the Aivazis-Collins-Olness-Tung scheme

The approximate SACOT- χ scheme for heavy quark production in deep-inelastic scattering was initially formulated for the neutral current structure functions F 2 and F L . We extend this approach to the charged current case (also including F 3 ), and thereby complete the definitions for the most relevant inclusive structure functions. Furthermore, we implement these structure functions in the open-source code ++ which provides fast numerical evaluations over a wide kinematic range; this addition to the ++ code is publicly available, with details provided in the Appendix. This SACOT- χ implementation enables detailed numerical insights on the mass dependence of the structure functions and cross sections in the ( x , Q 2 ) -plane for both neutral and charged current processes. We consider kinematic regions relevant for the experimental measurements from fixed-target ν DIS experiments (NuTeV, CCFR, and Chorus) and HERA, and also projections for the upcoming EIC. In particular, the ν DIS experiments reveal a surprisingly strong dependence on the mass effects, offering valuable insights that may help resolve long-standing challenges in accurately describing these datasets.