2026/07/19 by Long-Cheng Gui, Wei Sun, Ying Chen +3
#hep-lat #hep-ex #hep-ph
We investigate the mixing between the lowest-lying scalar glueball and the ss meson in Nf=1 lattice quantum chromodynamics (QCD) utilizing an anisotropic 163 × 128 lattice ensemble at a lattice spacing as≈ 0.148 \rmfm. By solving a generalized eigenvalue problem (GEVP) for the optimized glueball and ss scalar operators in the JPC = 0++ channel, the masses of the two lowest-lying eigenstates are determined to be m1 = 1.290(20) GeV and m2 = 1.777(49) GeV. By extracting the couplings of these mass eigenstates to the glueball and ss operators, we determine a substantial mixing angle |θ| ≈ 40.7(2.7)^∘ and a large mixing energy xs = 239(24) MeV. These results indicate a strong glueball-ss mixing in the scalar sector, providing important non-perturbative inputs for understanding the nature of the experimental isoscalar scalar mesons. The continuum limit of the mixing energy and its quark mass dependence need to be investigated in the future.