First Evidence of $N_f$-Dependence in the QCD Interquark Potential

We present a lattice calculation of the interquark potential between static quarks in a ``full’’ QCD simulation with 2 flavours of dynamical Wilson-quarks at three intermediate sea-quark masses. We work at $\beta =5.6$ on lattice size of ${16}^3\times 32$ with 100 configurations per sea-quark mass. We compare the full QCD potential with its quenched counterpart at equal lattice spacing, $a^{-1}\simeq 2.0$ GeV, which is at the onset of the quenched scaling regime. We find that the full QCD potential lies consistently below that of quenched QCD. We see no evidence for string-breaking effects on these lattice volumes, $V\simeq (1.5\mathrm{f}\mathrm{m}{)}^3$.