Tomography of high-twist proton structure through ep elastic scattering

We present the first high-twist study of the proton form factors F1,2(Q²) F 1 , 2 ( Q 2 ) in ep elastic scattering based on the perturbative QCD kT k T factorization, Q² Q 2 being momentum transfer squared. It is motivated by unexpectedly large higher-power contributions from subleading-twist light-cone distribution amplitudes (LCDAs), which are attributed to the enhancement in endpoint regions of parton momentum fractions. We highlight that the endpoint enhancement, tamed by the kT k T resummation effect, is crucial for accommodating the approximate scaling behavior of the Q⁴F₁(Q²) Q 4 F 1 ( Q 2 ) data at intermediate Q²~ O(10) Q 2 ∼ O ( 10 ) GeV ² 2 . The proton LCDAs up to twist 6 are then extracted, and verified by the charge-parity asymmetries observed in hadronic heavy baryon decays. Our work provides new insights into the proton three-dimensional structure and manifests the precision requirement for reliable perturbative analyses of baryonic exclusive processes.