RT Journal Article T1 A Nakanishi-based model illustrating the covariant extension of the pion GPD overlap representation and its ambiguities A1 Chouika, N. A1 Mezrag, Cédric A1 Moutarde, Hervé A1 Rodríguez Quintero, José AB A systematic approach for the model building of Generalized Parton Distributions (GPDs), based on their overlap representation within the DGLAP kinematic region and a further covariant extension to the ERBL one, is applied to the valence-quark pion’s case, using light-front wave functions inspired by the Nakanishi representation of the pion Bethe–Salpeter amplitudes (BSA). This simple but fruitful pion GPD model illustrates the general model building technique and, in addition, allows for the ambiguities related to the covariant extension, grounded on the Double Distribution (DD) representation, to be constrained by requiring a soft-pion theorem to be properly observed. PB Elsevier SN 0370-2693 YR 2018 FD 2018-03 LK http://hdl.handle.net/10272/16110 UL http://hdl.handle.net/10272/16110 LA eng NO Chouika, N., Mezrag, C., Moutarde, H., & Rodríguez-Quintero, J. (2018). A Nakanishi-based model illustrating the covariant extension of the pion GPD overlap representation and its ambiguities. Physics Letters B, 780, 287-293. https://doi.org/10.1016/j.physletb.2018.02.070 NO The authors would like to thank J-F. Mathiot, C.D. Roberts, G. Salme and C. Shi for valuable discussions and comments. This work is partly supported by the Commissariat a l'Energie Atomique et aux Energies Alternatives, the GDR QCD "Chromodynamique Quantique", the ANR-12-MONU-0008-01 "PARTONS" and the Spanish ministry Research Project FPA2014-53631-C2-2-P. DS Repositorio Institucional de la Universidad de Huelva RD 1 jun 2026