Meson resonances at large N-C: Complex poles vs Breit-Wigner masses
The rigorous quantum mechanical definition of a resonance requires determining the pole position in the second Riemann sheet of the analytically continued partial wave scattering amplitude in the complex Mandelstam s variable plane. For meson resonances we investigate the alternative Breit–Wigner (B...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2009 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/20830 |
| Acceso en línea: | http://hdl.handle.net/10261/20830 |
| Access Level: | acceso abierto |
| Palabra clave: | Chiral symmetries Large N-C Unitarization Resonances Scalar meson |
| Sumario: | The rigorous quantum mechanical definition of a resonance requires determining the pole position in the second Riemann sheet of the analytically continued partial wave scattering amplitude in the complex Mandelstam s variable plane. For meson resonances we investigate the alternative Breit–Wigner (BW) definition within the large NC expansion. By assuming that the pole position is View the MathML source and exploiting unitarity, we show that the BW determination of the resonance mass differs from the pole position by View the MathML source terms, which can be extracted from ππ scattering data. For the case of the σ (f0(600)) pole, the BW scalar mass is predicted to occur at not, vert, similar700 MeV while the true value is located at not, vert, similar800 MeV. |
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