%0 Journal Article
%A Peláez Sagredo, José Ramón
%A Pennington, M. R.
%A Ruiz de Elvira, Jacobo
%A Wilson, D. J.
%T Chiral perturbation theory, the 1/N_c expansion and Regge behavior determine the structure of the lightest scalar meson
%D 2011
%@ 1550-7998
%U https://hdl.handle.net/20.500.14352/44814
%X 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.
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