| DATE: |
2005-05-12 16:00 - |
| PLACE: |
Kenkyu Honkan Rm. 220 |
| TITLE: |
Lattice study for penta-quark states |
| CONTACT: |
tango |
| SPEAKER: |
Dr. Takashi Umeda (YITP, Kyoto Univ.) |
| LANGUAGE: |
Japanese |
| ABSTRACT: |
We study spin $\frac12$ hadronic states in quenched lattice QCD to search for a possible $S=+1$ pentaquark resonance.
Simulations are carried out on $83\times 24$, $103\times 24$, $123\times 24$ and $163\times 24$ lattices at $\beta$=5.7 at the quenched level with the standard plaquette gauge action and the Wilson quark action.
We adopt two independent operators with the quantum numbers $(I,J)=(0,\frac12)$ to construct $2\times 2$ correlation matrices.
After the diagonalization of the correlation matrices, we successfully obtain the energies of the lowest state
and the 2nd-lowest state in this channel.
The analysis of the volume dependence of the energies and spectral weight factors indicates that a resonance state is likely to exist slightly above the NK threshold in $(I,J^P)=(0,\frac12^-)$ channel.
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