# Alternative Large Nc Schemes and Chiral Dynamics

## TL;DR

This paper compares different large Nc schemes in pion-pion scattering, revealing how they relate to chiral dynamics and potentially clarifying longstanding puzzles in low-energy QCD and technicolor models.

## Contribution

It introduces a comparison between single and two index quark schemes and their impact on pion scattering amplitudes within large Nc approaches.

## Key findings

- Different Nc schemes have distinct relationships to chiral dynamics.
- The schemes can explain pion scattering up to about 1 GeV.
- Insights may improve understanding of large Nc and technicolor models.

## Abstract

We compare the dependences on the number of colors of the leading pion pion scattering amplitudes using the single index quark field and two index quark fields. These are seen to have different relationships to the scattering amplitudes suggested by chiral dynamics which can explain the long puzzling pion pion s wave scattering up to about 1 GeV. This may be interesting for getting a better understanding of the large Nc approach as well as for application to recently proposed technicolor models.