Model Dependent Analyses on the Nc Dependence of the σ Pole Trajectory
Abstract
We explore the nature of the σ or f0(600) meson using large Nc technique, assuming that the σ pole dominates low energy physics in the IJ=00 channel. We trace the Nc dependence of the σ pole position using [1,1] Padé approximation of SU(3) chiral amplitude, [1,2] Padé approximation of SU(2) chiral amplitudes, and the PKU parametrization form. We find that in all 3 cases the σ pole moves to the real axis of the complex s-plane. Finally we construct a pedagogical example using the SU(2) Padé amplitude to show that when the analyticity property of the scattering amplitude is violated, it is possible that the σ pole resides on the complex s plane when Nc is large.
- Publication:
-
Modern Physics Letters A
- Pub Date:
- 2007
- DOI:
- 10.1142/S0217732307023304
- arXiv:
- arXiv:hep-ph/0503195
- Bibcode:
- 2007MPLA...22..711S
- Keywords:
-
- σ meson;
- Nc dependence;
- ππ scattering;
- High Energy Physics - Phenomenology
- E-Print:
- Talk presented at Conference on Non-Perturbative Quantum Field Theory: Lattice and Beyond, Guangzhou, China, Dec.16--18, 2004