Fernández Ramírez, CésarMoya de Guerra, E.Udías, J. M.2024-12-092024-12-092006-04-18Fernández-Ramírez, C., Guerra, E. M. de ., & Udías, J. M. (2006, April 18). Hints on the quadrupole deformation of the Δ(1232). Physical Review C. American Physical Society. http://doi.org/10.1103/physrevc.73.0422012469-9985; 2469-9993https://doi.org/10.1103/PhysRevC.73.042201https://hdl.handle.net/20.500.14468/24757This is an Accepted Manuscript of an article published by American Physical Society in "Physical Review C 73 (4)", available at: https://doi.org/10.1103/PhysRevC.73.042201Este es el manuscrito aceptado del artículo publicado por American Physical Society en "Physical Review C 73 (4)", disponible en línea: https://doi.org/10.1103/PhysRevC.73.042201The 𝐸⁢2/𝑀⁢1 ratio (EMR) of the Δ(1232) is extracted from the world data in pion photoproduction by means of an effective Lagrangian approach (ELA). This quantity has been derived within a crossing symmetric, gauge invariant, and chiral symmetric Lagrangian model which also contains a consistent modern treatment of the Δ(1232) resonance. The bare 𝑠-channel Δ(1232) contribution is well isolated and final state interactions (FSI) are effectively taken into account fulfilling Watson's theorem. The obtained EMR value, EMR =(−1.30±0.52)%, is in good agreement with the latest lattice QCD calculations [Phys. Rev. Lett. 94, 021601 (2005)] and disagrees with results of current quark model calculations.eninfo:eu-repo/semantics/openAccessartículo