RT Book, Section T1 Recent progress on light scalar mesons A1 Peláez Sagredo, José Ramón AB This is a brief account of the recent developments on the determination of the mass and widths of the much debated scalar mesons, paying particular attention to the causes of major revision of the σ or f_0(500) meson in the last edition of the Review of Particle Physics, which has finally acknowledged that the situation concerning the mass and width of this controversial state has been settled, although this was already well-known to scalar meson practitioners for about a decade. I will briefly comment on the dispersive approach, followed by several groups, which seems to have been the most decisive in support of the existence and precise determinations of scalar meson properties. PB Universidad Complutense de Madrid. Dept Fis Teor 2. Fac CC Fisicas SN 978-0-7354-1242-2 YR 2014 FD 2014 LK https://hdl.handle.net/20.500.14352/35789 UL https://hdl.handle.net/20.500.14352/35789 LA eng NO © 2014 AIP Publishing.ISSN: 0094-243XConferencia:2nd Russian-Spanish Congress on Particle and Nuclear Physics at all Scales, Astroparticle Physics and Cosmology (2. 2013. St Petersburg, Rusia).I would very much like to thank the organizers for their warm hospitality, particularly Sergey Afonin, Sasha Andrianov and Domenec Espriu, for inviting me to give this review and nice organization of the workshop.This work is supported in part by the Spanish Research contract , FPA2011-27853-C02-02 and the EU FP7 HadronPhysics3 project. NO Unión Europea. FP7 NO Ministerio de Economía y Competitividad (MINECO) DS Docta Complutense RD 12 abr 2025