Year: 2004
Type: article
Abstract: We study the dependence on the number of colors of the leading $\ensuremath{\pi}\ensuremath{\pi}$ scattering amplitude in chiral dynamics. We demonstrate the existence of a critical number of colors for and above which the low energy $\ensuremath{\pi}\ensuremath{\pi}$ scattering amplitude computed from the simple sum of the current algebra and vector meson terms is crossing symmetric and unitary at leading order in a truncated and regularized ${1/N}_{c}$ expansion. The critical number of colors turns out to be ${N}_{c}=6$ and is insensitive to the explicit breaking of chiral symmetry. Below this critical value, an additional state is needed to enforce the unitarity bound; it is a broad one, most likely of a ``four quark'' nature.
Language: Latvian
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2008382271