Penta-quark (5Q) baryons are studied using anisotropic lattice QCD for high-precision measurement of temporal correlators. A non-NK-type interpolating field is employed to study the 5Q states with J^P=1/2^{\pm} and I=0. In J^P=1/2^+ channel, the lowest-lying state is found at m_{5Q} \simeq 2.25 GeV, which is too massive to be identified as the Theta^+(1540). In J^P=1/2^- channel, the lowest-lying state is found at m_{5Q} \simeq 1.75 GeV. To distinguish a compact 5Q resonance state from an NK scattering state, a new method with ``hybrid boundary condition (HBC)'' is proposed. As a result of the HBC analysis, the observed state in the negative-parity channel turns out to be an NK scattering state.
@article{arxiv.hep-lat/0501022,
title = {Penta-quark in Anisotropic Lattice QCD},
author = {N. Ishii and T. Doi and H. Iida and M. Oka and F. Okiharu and H. Suganuma},
journal= {arXiv preprint arXiv:hep-lat/0501022},
year = {2015}
}
Comments
A talk presented at 10th International Conference BARYONS04, Ecole Polytechnique, Palaiseau, France, 25-29, Oct 2004; A single sentence is added in Sect.1