Disentangle higher-twist and target-mass effects in the DIS-to-SIS transition

Disentangle nuclear higher-twist and target-mass corrections in order to characterize more precisely the transition between the deep-inelastic-scattering and shallow-inelastic-scattering regimes for nuclear targets.

Background

The nCTEQ26 analysis extends the fitted kinematic range to lower momentum transfers and higher Bjorken-x values, where conventional deep-inelastic-scattering descriptions approach the shallow-inelastic-scattering region. The authors include target-mass and deuteron corrections but omit higher-twist corrections because their implementation did not improve the fit description.

The separation of target-mass and higher-twist contributions remains unresolved, particularly for nuclear targets and in the transition region relevant to high-x charged-lepton and neutrino data. Establishing this separation is important for reliable nPDF extraction and for interpreting low-energy nuclear-scattering measurements.

References

Nevertheless, further investigation is needed to disentangle the HT and TMC contributions and to more precisely characterize the transition between the DIS and SIS regimes.

— nCTEQ26 nuclear parton distribution functions  (2610.13633 - Collaboration et al., 9 Oct 2026) in Section 3.1, subsection “Charged-lepton DIS data”