Speaker
Description
We present new Monte-Carlo tools for precision phenomenology in longitudinally polarized scattering processes, providing next-to-leading order QCD predictions matched to parton showers (NLO+PS) within the POWHEG BOX framework for di-jet production in polarized proton–proton collisions and polarized deep inelastic scattering. The generators are designed to deliver fully differential predictions for relevant observables to current and future spin-physics programs. We discuss the extensions required to consistently incorporate polarized initial states in the POWHEG formalism and study a range of observables for RHIC and for the upcoming Electron-Ion Collider. We assess the impact of parton-shower effects and selection criteria on key distributions, identifying kinematic regions where these effects are non-negligible and improve agreement with data or with higher-order predictions.