Discrete contribution to psi ' -> J/psi plus gamma gamma
The decay mode ψ ( 2 S ) → J / ψ + γ γ is proposed in order to experimentally identify the effects of the coupling of charmonium states to the continuum D ¯¯¯ D states. To have a better understanding of such a two-photon decay process, in this work we restrict ourselves to investigate the contributi...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2011 |
| País: | España |
| Institución: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repositorio: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:2445/18344 |
| Acceso en línea: | https://hdl.handle.net/2445/18344 |
| Access Level: | acceso abierto |
| Palabra clave: | Reaccions nuclears Partícules (Física) Nuclear reactions Particles (Nuclear physics) |
| Sumario: | The decay mode ψ ( 2 S ) → J / ψ + γ γ is proposed in order to experimentally identify the effects of the coupling of charmonium states to the continuum D ¯¯¯ D states. To have a better understanding of such a two-photon decay process, in this work we restrict ourselves to investigate the contribution of the discrete part, in which the photons are mainly produced via the intermediate states χ c J ( n P ) . Besides calculating the resonance contributions of χ c J ( 1 P ) ( J = 0 , 1 , 2 ) , we also take into account the contributions of the higher excited states χ c J ( 2 P ) and the interference effect among the 1 P and 2 P states. We find that the contribution of the 2 P states and the interference terms to the total decay width is very tiny. However, for specific regions of the Dalitz plot, off the resonance peaks, we find that these contributions are sizable and should also be accounted for. We also provide the photon spectrum and study the polarization of J / ψ . |
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