The Spectrum and Scale Setting on 2+1-flavor NME Lattices

Abstract

This paper describes the thirteen ensembles, named NME, generated with 2+1-flavor Wilson-clover fermions by the JLab/W\&M/LANL/MIT/Marseille collaborations, and presents an analysis of the meson and baryon spectrum, decay constants $f_{\pi }$ and $f_K$, flow scales $t_0$ and $w_0$, and time histories of the $\Theta$ and Weinberg operators under gradient flow. Using these quantities, the physical point values of the two flow scales, $t_0^{\mathrm{Phy}}$ and $w_0^{\mathrm{Phy}}$, and the ratio ${f_K/f_{\pi }}^{\mathrm{Phy}}$ are determined. The masses of the octet and decuplet baryons are analyzed using both the next-to-leading order (NLO) and the next-next-to-leading order (NNLO) ansatz from heavy baryon chiral perturbation theory (HB$\chi$PT). The NNLO fit to the octet baryons, $M_N$, $M_{\Sigma }$, $M_{\Lambda }$ and $M_{\Xi }$, is preferred while the corresponding fits to the decuplet Omega mass, $M_{\Omega }$, are not distinguished. We also present a study of the autocorrelations in the data and show that there is no evidence, even at large flow time, of the freezing of the topological charge or the Weinberg three-gluon operator.

Comments: 23 figures, 20 tables