2026-06-28T14:57:57Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/82702024-09-04T16:35:22Zcom_20.500.14352_14col_20.500.14352_15

00925njm 22002777a 4500 dc Peláez Sagredo, José Ramón author Rodas, Arkaitz author Ruiz De Elvira Carrascal, Jacobo author 2021-06-16 For several decades, the sigma/f(0)(500) and kappa/K*(0)(700) resonances have been subject to long-standing debate. Both their existence and properties were controversial until very recently. In this tutorial review, we compare model-independent dispersive and analytic techniques versus unitarized Chiral Perturbation Theory, when applied to the lightest scalar mesons sigma/f(0)(500) and kappa/K*(0)(700). Generically, the former have settled the long-standing controversy about the existence of these states, providing a precise determination of their parameters, whereas unitarization of chiral effective theories allows us to understand their nature, spectroscopic classification and dependence on QCD parameters. Here we review in a pedagogical way their uses, advantages and caveats. 1951-6355 10.1140/epjs/s11734-021-00142-9 https://hdl.handle.net/20.500.14352/8270 http://dx.doi.org/10.1140/epjs/s11734-021-00142-9 https://link.springer.com/ Precision dispersive approaches versus unitarized chiral perturbation theory for the lightest scalar resonances sigma/f(0)(500) and kappa/K*(0)(700)