Five-quark (5Q) picture of Lambda(1405) is studied using quenched lattice QCD with an exotic 5Q operator of N\bar{K} type. To discreminate mere N\bar{K} and \Sigma\pi scattering states, Hybrid Boundary Condition (HBC), a flavor-dependent boundary condition, is imposed on the quark fields along spatial direction. 5Q mass m_{5Q}\simeq 1.89 GeV is obtained after the chiral extrapolation to the physical quark mass region, which is too heavy to be identified with Lambda(1405). Then, Lambda(1405) seems neither a pure 3Q state nor a pure 5Q state, and therefore we present an interesting possibility that Lambda(1405) is a mixed state of 3Q and 5Q states.
@article{arxiv.0707.0079,
title = {Five-quark picture of Lambda(1405) in anisotropic lattice QCD},
author = {Noriyoshi Ishii and Takumi Doi and Makoto Oka and Hideo Suganuma},
journal= {arXiv preprint arXiv:0707.0079},
year = {2008}
}
Comments
A talk given at Yukawa International Seminar(YKIS) 2006 NEW FRONTIERS IN QCD --Exotic Hadrons and Hadronic Matter--, Kyoto, Japan, Nov. 20-Dec.8 2006, 4 pages, 2 figures