Penta-quark baryon from the QCD Sum Rule
arXiv:hep-ph/0309271 · doi:10.1016/j.physletb.2003.12.018
Abstract
Exotic penta-quark baryon with strangeness +1, Θ^+, is studied in the QCD sum rule approach. We derive sum rules for the positive and negative parity baryon states with J=1/2 and I=0. It is found that the standard values of the QCD condensates predict a negative parity Θ^+ of mass \simeq 1.5 GeV, while no positive parity state is found. We stress the roles of chiral-odd condensates in determining the parity and mass of Θ^+.
7 pages, 3 figures, To be published in Phys.Lett.B