We compute the improvement coefficient csw that multiplies the Sheikholeslami-Wohlert term as a function of the bare gauge coupling for two flavour QCD. We discuss several aspects concerning simulations with improved dynamical Wilson fermions.

We compute the improvement coefficient csw that multiplies the Sheikholeslami-Wohlert term as a function of the bare gauge coupling for two flavour QCD. We discuss several aspects concerning simulations with improved dynamical Wilson fermions.

We study the charmonium spectrum including higher spin and exotic states. We use the Sheikholeslami-Wilson (clover) action for N f = 2 sea quarks as well as for the charm valence quark. In order to access excited states we apply a variational method with a basis of highly optimized operators.

SSOR preconditioning of fermion matrix inversions which is parallelized using a locally-lexicographic lattice sub-division has been shown to be very efficient for standard Wilson fermions. We demonstrate here the power of this method for the Sheikholeslami-Wohlert improved fermion action and for a renormalization group improved action incorporating couplings of the lattice fermion fields up to ...

We have results from light hadron simulations in quenched QCD at β = 6.0 and 6.2 using non-perturbatively improved Sheikholeslami–Wohlert fermions in an effort to remove all O(a) effects. From looking at hadron masses and splittings and the RG-invariant quark masses (where we have one point at β = 5.7) we suggest this is plausible even with the limited data set. The interpretation of the decay ...

We generalize l ocal l exicographic SSOR preconditioning for the Sheikholeslami-Wohlert improved Wilson fermion action and the truncated perfect free fermion action. In our test implementation we achieve performance gains as known from SSOR preconditioning of the standard Wilson fermion action.

The matrix element of the electromagnetic current between pion states is calculated in quenched lattice QCD at a temperature of T = 0.93 T c. The nonperturbatively improved Sheikholeslami-Wohlert action is used together with the corresponding O(a) improved vector current. The electromagnetic vertex function is extracted for pion masses down to 360 MeV and momentum transfers Q 2 ≤ 2.7 GeV

The contributions of the improved fermion action of Sheikholeslami and Wohlert to the two loop coefficient of the expansion of the Schrödinger functional coupling in terms of the lattice coupling are calculated for the gauge group SU(3). These coefficients are required for the second order relation of lattice data to the MS-coupling. By taking into account all improvement coefficients we are ab...