Document Type
Article
Date
7-5-2007
Language
English
Disciplines
Physics
Description/Abstract
We present a detailed study of a linear sigma model containing one chiral nonet transforming under U(1)_A as a quark-antiquark composite and another chiral nonet transforming as a diquark-anti diquark composite (or, equivalently from a symmetry point of view, as a two meson molecule). The model provides an intuitive explanation of a current puzzle in low energy QCD: Recent work has suggested the existence of a lighter than 1 GeV nonet of scalar mesons which behave like four quark composites. On the other hand, the validity of a spontaneously broken chiral symmetric description would suggest that these states be chiral partners of the light pseudoscalar mesons, which are two quark composites. The model solves the problem by starting with the two chiral nonets mentioned and allowing them to mix with each other. The input of physical masses in the SU(3) invariant limit for two scalar octets and an "excited" pion octet results in a mixing pattern wherein the light scalars have a large four quark content while the light pseudoscalars have a large two quark content. One light isosinglet scalar is exceptionally light. In addition, the pion pion scattering is also studied and the current algebra theorem is verified for massless pions which contain some four quark admixture.
Recommended Citation
Schechter, Joseph; Fariborz, Amir H.; and Jora, Renata, "Two Chiral Nonet Model with Massless Quarks" (2007). Physics - All Scholarship. 263.
https://surface.syr.edu/phy/263
Source
Harvested from Arxiv.org
Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.
Additional Information
22 pages, 8 figures More information available at http://arxiv.org/abs/0707.0843