Probing the jet transport coefficient of cold nuclear matter in electron-ion collisions

Abstract We investigate the transverse momentum broadening~(TMB) of particle production in upcoming electron–ion collision experiments, an important manifestation of jet transport in cold nuclear matter. By considering the effects of parton multiple scattering in nuclear medium within the high-twist expansion framework in perturbative QCD, we calculate the TMB of single hadron production in semi-inclusive measurements, as well as the nuclear enhancement of the transverse momentum imbalance for di-hadron and heavy-meson pair productions. A central input to our calculations is the effective jet transport coefficient $\hat{q} = \hat{q}(x,Q^2)$, which depends on the parton momentum fraction $x$ and the probing scale $Q^2$. This quantity is obtained from an improved global analysis of existing data, with uncertainties quantified using the Hessian method. Our predictions show a clear kinematic and color‑state dependence of the nuclear‑induced broadening and imbalance. These results demonstrate that future measurements of TMB will provide valuable insights into the kinematic dependence of jet transport properties, thereby substantially advancing the jet tomography of cold nuclear matter.