We give two ”complementary” descriptions of the curve Γ parametrizing doubleBloch solutions to the difference analogue of the Lamé equation. The curve depends on a positive integer number l and two continuous parameters: the ”lattice spacing” η and the modular parameter τ . Apart from being a covering of the elliptic curve with the modular parameter τ , Γ is a hyperelliptic curve of genus 2l. W...

Abstract We construct the effective field theory appropriate for describing the low energy behavior of anisotropic Wilson lattice actions and the O(a) improved variant thereof. We then apply this effective field theory to the hadron spectrum and dispersion relations, focussing on the corrections due to the anisotropy. We point out an important feature of anisotropic lattices regarding the Aoki-...

We present results for the leptonic decays of heavy-light mesons in the quenched approximation and a preliminary result for fD s with dynamical fermions for N f = 2. We examine the systematic effects of extrapolating the decay constants from the charm to the bottom quark mass, and find this extrapolation to be under control. We present a preliminary result for f N f =2 Ds and compare to f N f =...

One of the important problems of high-temperature superconductivity is to understand and ultimately to control uxoid motion. Here we present data on the pressure dependence of the irreversibility line measured up to 2.5 GPa. We observe that the application of pressure changes the interplanar coupling by decreasing the c-axis length, without signi cantly disturbing the intraplanar superconductiv...

Answering a question raised by Terwijn, we give a lattice-theoretic characterization of the intervals of the Muchnik lattice as a subset of the distributive lattices, valid for all intervals satisfying a cardinality constraint on the size of antichains.

We compute the hadron mass spectrum, the quark masses and the meson decay constants in quenched lattice QCD with non-perturbatively O(a) improved Wilson fermions. The calculations are done for two values of the coupling constant, β = 6.0 and 6.2, and the results are compared with the predictions of ordinary Wilson fermions. We find that the improved action reduces lattice artifacts as expected.

We report calculations of B K using two flavours of dynamical clover-improved Wilson lattice fermions and look for dependence on the dynamical quark mass at fixed lattice spacing. We see some evidence for dynamical quark effects. In particular B K decreases as the sea quark masses are reduced towards the up/down quark mass. Our meson masses are quite heavy and a firm prediction of B K is a task...

The composition dependence of the Yb valence and of the thermal expansion have been studied in the YbGaxGe2−x system. X-ray diffraction reveals that singlephased samples isostructural to YbGaGe are obtained in the range of 0.9 ≤ x ≤ 1.5. The magnetic susceptibility shows that the systems are almost nonmagnetic below room temperature, indicating a stable Yb state for the x range 0.9 ≤ x ≤ 1.5. T...

We present initial calculations of nucleon matrix elements of twist-two operators with 2+1 flavors of domain wall fermions at a lattice spacing a = 0.084 fm for pion masses down to 300 MeV. We also compare the results with the domain wall calculations on a coarser lattice.

We consider the space–time variation of gauge couplings in brane world models induced by the coupling to a bulk scalar field. A variation is generated by the running of the gauge couplings with energy and a conformal anomaly while going from the Jordan to the Einstein frame. We indicate that the one-loop corrections cancel implying that one obtains a variation of the fine structure constant by ...