2026/07/16 by Cong Li
#hep-ph #hep-th
In this work, we investigate a cross-section-ratio-based inversion method for extracting distribution functions at the Electron--Ion Collider (EIC). Starting from the general factorization formula dσ= H ⊗ f, we show that, for an appropriate bremsstrahlung process and suitably chosen differential observables, the convolution structure can be reduced to a multiplicative form. On this basis, we define the ratio R = \fracdσexpdσhard, where dσexp is the experimentally measured differential cross section and dσhard is a perturbatively calculable theoretical input. We then establish the relation between R and the target distribution function f. Finally, we investigate how the theoretical input dσhard should be constructed when soft-photon radiation, finite-bin-width effects, and experimental acceptance are taken into account.