Accessing the Pion 3D Structure at US and China Electron-Ion Colliders

We present the first systematic feasibility study of accessing generalized parton distributions of the pion at an electron-ion collider through deeply virtual Compton scattering. Relying on state-of-the-art models for pion GPDs, we show that quarks and gluons interfere destructively, modulating the expected event rate and maximizing it when parton content is generated via radiation from valence dressed quarks. Moreover, gluons are found to induce a sign inversion for the beam-spin asymmetry in every model studied, being a clear signal for pinning down the regime of gluon superiority
We would like to thank P. Barry, H. Dutrieux, T. Meisgny, B. Pire, K. Raya, C. D. Roberts, D. Sokhan, Q.-T. Song, P. Sznajder, and J. Wagner for interesting discussions and stimulating comments. This work is supported by the University of Huelva under Grant No. EPIT-2020 (J.M.M. C.). F. S., J. R. Q., and J. S. acknowledge support from Ministerio de Ciencia e Innovación (Spain) underGrant No. PID2019–107844 GB-C22 and Junta de Andalucía, under the 2014-2020 FEDER Contracts No.UHU-1264517, No. P18-1321FR-5057 and No. PAIDI FQM-370. This project was supported by the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 824093. This work is supported in part in the framework of the GLUODYNAMICS project funded by the “P2IO LabEx” (No. ANR-10-LABX-0038) in the framework “Investissements d’Avenir” (No. ANR-11- IDEX-0003-01) managed by the Agence Nationale de la Recherche (ANR), France