On Lowest Lying ${\frac{1}{2}}^{-}$ Octet Baryons

Abstract

The recently proposed $N^{\ast }(890)$ $1/2^{-}$ baryon is studied in a flavor $SU(3)$ scheme with $K$ matrix unitarization, by fitting to low energy cross section and phase shift data. It is found that $N^{\ast }(890)$ co-exists with low lying poles in other channels, which have been extensively discussed in the literature, though they belong to different octets, in the $SU(3)$ limit. Hence the existence of $N^{\ast }(890)$ is further verified.

8 pages