Analyticity and the Nc Counting Rule of S Matrix Poles
Abstract
By studying ππ scattering amplitudes in the large-Nc limit, we clarify the Nc dependence of the S matrix pole position. It is demonstrated that analyticity and the Nc counting rule exclude the existence of S-matrix poles with {M},Γ ∼ O(1). Especially the properties of σ and f0(980) with respect to the 1/Nc expansion are discussed. We point out that in general tetra-quark resonances do not exist.
- Publication:
-
Modern Physics Letters A
- Pub Date:
- 2007
- DOI:
- arXiv:
- arXiv:hep-ph/0502199
- Bibcode:
- 2007MPLA...22...55X
- Keywords:
-
- 11.15.Pg;
- 11.55.Bq;
- 12.39.Fe;
- 14.40.Cs;
- Expansions for large numbers of components;
- Analytic properties of S matrix;
- Chiral Lagrangians;
- Other mesons with S=C=0 mass<
- 2.5 GeV;
- High Energy Physics - Phenomenology
- E-Print:
- This paper replaces hep-ph/0412175. The latter is withdrawn