3.80      1.36      1000
  3.60      0.90      2000       3.85      1.50      1000
  3.63      0.96      3000       3.90      1.65      1000
  3.65      1.00      4000       3.95      1.81      1000
  3.66      1.02      4000       4.00      1.98      4000
  3.68      1.07      3600       4.43      4.01      1600
  3.70      1.11      2000                           

  : Sample sizes at each $\beta$ value and the temperature in units of the (pseudo-) critical temperature $T_c$.

\[tab:configs\]

For our study of the strong interaction in terms of the quark anti-quark free energies in full QCD lattice configurations were generated for $2$-flavor QCD ($N_f$=2) on $16^3\times 4$ lattices with bare quark mass $ma$=0.1, [*i.e.*]{} $m/T$=0.4, corresponding to a ratio of pion to rho masses ($m_{\pi}/m_{\rho}$) at the (pseudo-) critical temperature of about $0.7$ ($a$ denotes the lattice spacing) [@Karsch:2000kv]. We have used Symanzik improved gauge and p4-improved staggered fermion actions. This combination of lattice actions is known to reduce the lattice cut-off effects in Polyakov loop correlation functions at small quark anti-quark separations seen as an improved restoration of the broken rotational symmetry. For any further details of the simulations with these actions see [@Allton:2002zi; @Allton:2003vx]. In Table \[tab:configs\] we summarize our simulation parameters, [*i.e.*]{} the lattice coupling $\beta$, the temperature $T/T_c$ in units of the pseudo critical temperature and the number of 