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Search for the S=+1 pentaquarks in quenched lattice QCD

Toru T. Takahashi·Takashi Umeda·Tetsuya Onogi·Teiji Kunihiro
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Abstract

We study spin $\frac12$ hadronic states in quenched lattice QCD to search for a possible $S=+1$ pentaquark resonance. Our work is the first systematic lattice QCD study which properly carries out the following analyses: {\it (1) the careful extraction of the first two low energy states with very high statistics and the variational method} and {\it (2) the study of volume dependences of eigenenergies and spectral weights to distinguish resonance states from scattering states}. Simulations are carried out on $8^3\times 24$, $10^3\times 24$, $12^3\times 24$ and $16^3\times 24$ lattices at $β$=5.7 with the standard plaquette gauge action and the Wilson quark action. Our result indicates the existence of a resonance state lying slightly above the NK threshold in $(I,J^P)=(0,\frac12^-)$ channel in quenched QCD.

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Toru T. Takahashi, Takashi Umeda, Tetsuya Onogi, Teiji Kunihiro. 2005-09-27. Search for the S=+1 pentaquarks in quenched lattice QCD. https://arxiv.org/abs/hep-lat/0509148

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