η-glueball mixing from Nf=2 lattice QCD

We perform the first lattice study on the mixing of the isoscalar pseudoscalar meson eta and the pseudoscalar glueball Gin the Nf 1/4 2 QCD at the pion mass m pi approximate to 350 MeV. The eta mass is determined to be m eta 1/4 714o6 thorn o16 thorn MeV. Through the Witten-Veneziano relation, this value can be matched to a mass value of similar to 981 MeV for the SU(3) counterpart of eta. Based on a large gauge ensemble, the eta - G mixing energy and the mixing angle are determined to be jxj 1/4 107o15 thorn o2 thorn MeV and j theta j 1/4 3.46o46 thorn degrees from the eta - G correlators that are calculated using the distillation method. We conclude that the eta - G mixing is tiny and the topology induced interaction contributes most of eta mass owing to the QCD UAo1 thorn anomaly.

Automated summary

We perform the first lattice study on the mixing of the isoscalar pseudoscalar meson eta and the pseudoscalar glueball Gin the Nf 1/4 2 QCD at the pion mass m pi approximate to 350 MeV. The eta mass is determined to be m eta 1/4 714o6 thorn o16 thorn MeV. Through the Witten-Veneziano relation, this value can be matched to a mass value of similar to 981 MeV for the SU(3) counterpart of eta. Based on a large gauge ensemble, the eta - G mixing energy and the mixing angle are determined to be jxj 1/4 107o15 thorn o2 thorn MeV and j theta j 1/4 3.46o46 thorn degrees from the eta - G correlators that are calculated using the distillation method. We conclude that the eta - G mixing is tiny and the topology induced interaction contributes most of eta mass owing to the QCD UAo1 thorn anomaly.