Evidence for the Two-Pole Structure of the {lambda}(1405) Resonance
- Departamento de Fisica Teorica and IFIC, Centro Mixto, Institutos de Investigacion de Paterna-Universidad de Valencia-CSIC, Apartado correos 22085, 46071, Valencia (Spain)
- Departament d'Estructura i Constituents de la Materia, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain)
The K{sup -}p{yields}{pi}{sup 0}{pi}{sup 0}{sigma}{sup 0} reaction is studied within a chiral unitary model. The distribution of {pi}{sup 0}{sigma}{sup 0} states forming the {lambda}(1405) shows, in agreement with a recent experiment, a peak at 1420 MeV and a relatively narrow width of {gamma}=38 MeV. The mechanism for the reaction is largely dominated by the emission of a {pi}{sup 0} prior to the K{sup -}p interaction leading to the {lambda}(1405). This ensures the coupling of the {lambda}(1405) to the K{sup -}p channel, thus maximizing the contribution of the second state found in chiral unitary theories, which is narrow and of higher energy than the nominal {lambda}(1405). This is unlike the {pi}{sup -}p{yields}K{sup 0}{pi}{sigma} reaction, which gives more weight to the pole at lower energy and with a larger width. The data of these two experiments, together with the present theoretical analysis, provide firm evidence of the two-pole structure of the {lambda}(1405)
- OSTI ID:
- 20699253
- Journal Information:
- Physical Review Letters, Vol. 95, Issue 5; Other Information: DOI: 10.1103/PhysRevLett.95.052301; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
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