Identification of non-ordinary mesons from the dispersive connection between their poles and their Regge trajectories: The resonance

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• 作者：J.T. Londergan ; J. Nebreda ; J.R. Pelaez ; A.P. Szczepaniak
• 关键词：Regge theory ; Light scalar mesons
• 刊名：Physics Letters B
• 出版年：5 February, 2014
• 年：2014
• 卷：729
• 期：Complete
• 页码：9-14
• 全文大小：700 K

文摘

We show how the Regge trajectory of a resonance can be obtained from its pole in a scattering process and analytic constraints in the complex angular momentum plane. The method is suited for resonances that dominate an elastic scattering amplitude. In particular, from the resonance pole in 蟺蟺 scattering, we obtain its linear Regge trajectory, characteristic of ordinary quark-antiquark states. In contrast, the pole鈥攖he sigma meson鈥攚hich dominates scalar isoscalar 蟺蟺 scattering, yields a nonlinear trajectory with a much smaller slope at the mass. Conversely, imposing a linear Regge trajectory for the , with a slope of typical size, yields an elastic amplitude at odds with the data. This provides strong support for the non-ordinary nature of the sigma meson.