Glueballs at finite temperature in quenched lattice QCD

Abstract

Using anisotropic lattices, glueballs at finite temperature are investigated in a large temperature range from 03Tc to 1.9Tc in quenched lattice QCD, where Tc is the critical temperature. Optimized glueball operators are used in the calculations. It is found that in all 20 symmetry channels, the pole masses MG of glueballs remain almost constants when the temperature approaches Tc from below, and start to reduce gradually with the temperature going above Tc. The glueball correlators in 0++, 0−+, and 2++ channels are also analyzed based on the Breit‐Wigner ansatz by assuming a thermal width Γ to the pole mass ω0. We found that while ω0’s are insensitive to T in the whole temperature range, the Γ’s exhibit distinct behavior below and above Tc. They are only a few percent of ω0 when T<Tc, but grow rapidly when T>Tc and reach values of roughly Γ∼ω0/2 at T≈1.9Tc.