We show that the hierarchy of quantum correlations produced in deep-inelastic scattering (DIS) can serve as a novel probe of the proton's nonperturbative structure. Specifically, we show that quantum entanglement, discord, steering, and magic provide nontrivial and complementary sensitivities to the nucleon's parton distribution functions (PDFs), particularly those encoding the transverse-spin polarization of the interacting quark. This connection leads to a unique probe of the proton's parton-level tensor charges with implications for beyond Standard Model (BSM) physics searches. We propose how quantum information measures can be utilized for precision studies of hadron structure at DIS experiments like the upcoming Electron-Ion Collider (EIC).
We study high-energy photons produced at a lepton collider that convert into an $e^+e^-$ pair in the detector, as a tool for measuring quantum information observables. We consider single- and double-conversion processes in $e^+e^- \to \gamma\gamma$ and $e^+e^- \to e^+e^-\gamma$. Single conversions enable an in situ extraction of the spin-analyzing power, while double conversions probe polarization correlations. Focusing on the Belle-II detector, we show that, depending on the reconstruction resolution of the opening angle of the conversion $e^+e^-$ pair, quantum correlations of the diphoton system can be probed. In particular, measurements of violations of the Bell inequality, quantum discord, concurrence, nonstabilizerness, and steerability with spatially separated GeV-scale photons can be made at high significance.
Carlos Henrique de Lima, N. McGinnis, D. McKeen· 0 citations