  The persistent current of correlated electrons in a continuous
one-dimensional ring with a single scatterer is calculated by solving the
many-body Schrodinger equation for several tens of electrons interacting via
the electron-electron (e-e) interaction of finite range. The problem is solved
by the configuration-interaction (CI) and diffusion Monte Carlo (DMC) methods.
The CI and DMC results are in good agreement. In both cases, the persistent
current $I$ as a function of the ring length $L$ exhibits the asymptotic
dependence $I \propto L^{-1-\alpha}$ typical of the Luttinger liquid, where the
power $\alpha$ depends only on the e-e interaction. The numerical values of
$\alpha$ agree with the known formula of the renormalisation-group theory.
