Glueball-mass estimates in lattice QCD

We show how the Langevin equation for SU(3) gauge fields can be used to compute glueball correlation functions at large separation. On a 6×6×6×6 lattice we estimate the mass of the lowest $0^{++}$ glueball by determining the corresponding correlation function at separations 0, 1, 2, and 3. Several values for the coupling constant are investigated which lie in a region where scaling behavior for the string tension is observed. Our preliminary study indicates $m_{0^{++}}=(240\mathrm{}\pm 70){\Lambda }_0$ or alternatively $m_{0^{++}}=(1.1\mathrm{}\pm 0.2)m_{\rho }$.