ar X iv : h ep - l at / 9 90 91 10 v 2 1 7 D ec 1 99 9 1 Improved

ar X iv : h ep - l at / 9 90 91 10 v 1 1 4 Se p 19 99 1 Improved Landau Gauge Fixing and Discretisation Errors ∗

Lattice discretisation errors in the Landau gauge condition are examined. An improved gauge fixing algorithm in which O(a 2) errors are removed is presented. O(a 2) improvement of the gauge fixing condition displays the secondary benefit of reducing the size of higher-order errors. These results emphasise the importance of implementing an improved gauge fixing condition.

ar X iv : h ep - l at / 9 91 20 16 v 1 9 D ec 1 99 9 NON PERTURBATIVE QCD

This series of lectures consists of two parts. In the first part the foundations of perturbative and non perturbative formulation are discussed. The ambiguity in the definition of vacuum condensates is then analyzed. In the second part the symmetry patterns of the deconfining phase transition are discussed.

ar X iv : h ep - p h / 99 12 39 3 v 1 1 7 D ec 1 99 9 Final - state interaction phase difference in J / ψ → ρη and ωη decays

Final-state interaction phase difference in J/ψ → ρη and ωη decays Abstract It is shown that the study of the ω − ρ 0 interference pattern in the J/ψ → (ρ 0 + ω)η → π + π − η decay provides the evidence for the large (nearly 90 •) relative phase between the one-photon and the three-gluon decay amplitudes.

ar X iv : h ep - p h / 99 12 28 8 v 2 1 5 D ec 1 99 9 Lattice Calculations and Hadron Physics

ar X iv : h ep - l at / 9 90 91 16 v 1 1 4 Se p 19 99 The flavour and quark mass dependence of thermodynamic quantities in lattice

The dependence of thermodynamic properties of QCD on the number of quark flavours is investigated. Lattice results for the equation of state are presented for 2, 2+1 and 3 quark flavours. The simulations have been performed with the improved p4-staggered fermion and a Symanzik improved gluon action on lattices of size 16 3 × 4 and 16 4 .