QCD with dynamical Wilson fermions

Abstract

We present results from a study of QCD with two flavors of Wilson fermions using the hybrid Monte Carlo algorithm, which incorporates the effects of fermion loops exactly. We evaluate the performance of the algorithm and its potential for large-scale computations. We argue that in the best case the algorithm slows down as $V^{\frac{5}{4}}{m_q}^{-\frac{13}{4}}$ at a fixed gauge coupling. We present improved algorithms for calculating the inverse and the determinant of the Wilson fermion operator. Results for the finite-temperature transition on 4×$6^3$ and 6×$8^3$ lattices are presented at $\beta =5.2-5.6\mathrm{}$. We also give Wilson loop expectation values obtained on $8^4$ lattices at $\beta =5.3\mathrm{}$ for six values of $\kappa$. The data show evidence for screening in the $q\overline{q}$ potential. Lastly, on comparing Wilson and staggered-fermion results we find that $\beta =5.3\mathrm{}$ is far from the scaling region.