2019 Impact factor 2.176
Hadrons and Nuclei
Eur. Phys. J. A 7, 441-448

Multiquark picture for $\Sigma$ (1620)

Seungho Choe

Special Research Centre for the Subatomic Structure of Matter, University of Adelaide, Adelaide, SA 5005, Australia

Received: 7 September 1998 / Revised version: 5 January 2000 Communicated by W. Weise

Abstract
In this work we report on a new QCD sum rule analysis to predict masses of the excited baryon states (e.g. $\Sigma$ (1620) and $\Lambda$ (1405)) by using multiquark interpolating fields ( $(q\bar{q})(qqq)$). For the $\Sigma$ (1620) we consider the $\bar{K}N$, $\pi\Sigma$, and $\pi\Lambda$ (I=1) multiquark interpolating fields. The calculated mass from those multiquark states is about 1.592 GeV. For the $\Lambda$ (1405) we first show the result using the $\pi^+\Sigma^- + \pi^0\Sigma^0 + \pi^-\Sigma^+$ (I=0) multiquark interpolating field, and compare the calculated mass to that of our previous result using the $\pi^0\Sigma^0$ multiquark state. We then show that the mass 1.405 GeV is well reproduced when using the $\bar{K}N$ (I=0) multiquark state. The uncertainties in our sum rules are also discussed.


Copyright Società Italiana di Fisica, Springer-Verlag 2000