Chiral perturbation theory, the 1/N_c expansion and Regge behavior determine the structure of the lightest scalar meson

The leading 1=N_c behavior of unitarized chiral perturbation theory distinguishes the nature of the ρ and the : The is a qq̅ meson, while the σ is not. However, semilocal duality between resonances and Regge behavior cannot be satisfied for larger N_c, if such a distinction holds. While the σ at N_c...

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Detalles Bibliográficos
Autores: Peláez Sagredo, José Ramón, Pennington, M. R., Ruiz De Elvira Carrascal, Jacobo, Wilson, D. J.
Tipo de recurso: artículo
Fecha de publicación:2011
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/44814
Acceso en línea:https://hdl.handle.net/20.500.14352/44814
Access Level:acceso abierto
Palabra clave:51-73
Energy sum-rules
Pion-pion scattering
N-C behavior
Elastic-scattering
One-loop
Resonances
Lagrangians
Amplitudes
Model
Nonet
Física-Modelos matemáticos
Física matemática
Descripción
Sumario:The leading 1=N_c behavior of unitarized chiral perturbation theory distinguishes the nature of the ρ and the : The is a qq̅ meson, while the σ is not. However, semilocal duality between resonances and Regge behavior cannot be satisfied for larger N_c, if such a distinction holds. While the σ at N_c = 3 is inevitably dominated by its di-pion component, unitarized chiral perturbation theory also suggests that as N_c increases above 6–8, the σ may have a subdominant qq̅ fraction up at 1.2 GeV. Remarkably this ensures semilocal duality is fulfilled for the range of Nc ≤ 15–30, where the unitarization procedure adopted applies.