Suchergebnisse

We introduce a new family of generalized parton distribution models able to fulfill by construction all the theoretical properties imposed by QCD. These models are built on standard parton distribution functions and extended to off-forward kinematics through a well-defined procedure. We apply this strategy on the pion, first handling a simple but insightful algebraic model, and then exploiting state-of-the-art computations obtained in continuum QCD. We compare these models with a more standard one relying on an xFitter extraction of the pion parton distribution functions. The results for both quark and gluon generalized parton distributions are presented and exploited for calculation of electromagnetic, gravitational, and Compton form factors. Results on the latter highlight the relevance of next-to-leading-order corrections, even in the so-called valence region ; We are grateful to Qin-Tao Song for kindly providing us the GFF data obtained from pion GDA. We would like to thank P. Barry, H. Dutrieux, T. Meisgny, B. Pire, K. Raya, C. D. Roberts, P. Sznajder, and J. Wagner for interesting discussions and stimulating comments. This work is supported by the University of Huelva under Grant No. EPIT2020 (J. M. M. C.). F. S., J. R. Q., and J. S. acknowledge support from Ministerio de Ciencia e Innovación (Spain) under Grant No. PID2019–107844 GB-C22; Junta de Andaluca, under the 2014–2020 FEDER Contracts No. UHU-1264517, No. P18-1321FR-5057 and 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 (ANR-10-LABX-0038)" in the framework "Investissements d'Avenir" (ANR-11-IDEX0003-01) managed by the Agence Nationale de la Recherche (ANR), France

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