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arXiv · hep-lat/0208070

Excited baryons from Bayesian priors and overlap fermions

F. X. Lee·S. J. Dong·T. Draper·I. Horvath·K. F. Liu·N. Mathur·J. B. Zhang
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Abstract

Using the constrained-fitting method based on Bayesian priors, we extract the masses of the two lowest states of octet and decuplet baryons with both parities. The calculation is done on quenched 16^3x28 lattices of a=0.2 fm using an improved gauge action and overlap fermions, with the pion mass as low as 180 MeV. The Roper state N(1440)1/2+ is clearly observed for the first time as the 1st-excited state of the nucleon from the standard interpolating field. Together with other baryons, our preliminary results indicate that the level-ordering of the low-lying baryon states on the lattice is largely consistent with experiment. The realization is helped by cross-overs between the excited 1/2+ and 1/2- states in the region of pion mass from 300 to 400 MeV.

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F. X. Lee, S. J. Dong, T. Draper, I. Horvath, K. F. Liu, N. Mathur, J. B. Zhang. 2002-08-29. Excited baryons from Bayesian priors and overlap fermions. https://doi.org/10.1016/s0920-5632(03)01543-3

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