We present results for QCD with 2 degenerate flavours of quark using a non-perturbatively improved action on a lattice volume of 16 × 32 where the bare gauge coupling and bare dynamical quark mass have been chosen to maintain a fixed physical lattice spacing and volume (1.71 fm). By comparing measurements from these matched ensembles, including quenched ones, we find evidence of dynamical quark...

Assuming the equivalence of FRW-cosmological models and their Newtonian counterparts, we propose using the Gauss law in arbitrary dimension a general relation between the Newtonian gravitational constant G and the gravitational coupling constant κ.

The first investigation of the microwave spectrum of ethylenediamine (NH CH –CH NH ) showed that in the gas phase this molecule occurs in two conformers which both exhibit a large amplitude tunneling motion corresponding to an interchange of the roles of the amino groups. In conformer I, the tunneling splitting is about 172 MHz while it is only 2.7 MHz in conformer II. In the paper an analysis ...

A variationally optimized perturbation, combined with renormalization group properties, can give approximations to certain nonperturbative quantities like the chiral symmetry breaking order parameters. We evaluate, up to third order in this modified perturbation, F π /Λ MS , where F π is the pion decay constant and Λ MS the basic QCD scale in the MS scheme. We obtain Λ

Working with a pion mass mπ ≈ 150 MeV, we study ππ and Kπ scattering using two flavours of non-perturbatively improved Wilson fermions at a lattice spacing a ≈ 0.071 fm. Employing two lattice volumes with linear spatial extents of Ns = 48 and Ns = 64 points and moving frames, we extract the phase shifts for p-wave ππ and Kπ scattering near the ρ and K∗ resonances. Comparing our results to those...

The secondary quinone anion radical QB(-) (SQB) in reaction centers of Rhodobacter sphaeroides interacts with Nδ of His-L190 and Np (peptide nitrogen) of Gly-L225 involved in hydrogen bonds to the QB carbonyls. In this work, S-band (∼3.6 GHz) ESEEM was used with the aim of obtaining a complete characterization of the nuclear quadrupole interaction (nqi) tensors for both nitrogens by approaching...

The unique high-resolution feature offered by 14N magic-angle spinning (MAS) NMR spectroscopy of ammonium ions has been used to characterize the crystal structures of various ammonium molybdates by their 14N quadrupole coupling parameters, i.e., CQ, the quadrupole coupling constant, and etaQ, the asymmetry parameter. Two polymorphs of diammonium monomolybdate, (NH4)2MoO4, recently structurally ...

In our first two papers on 14N nuclear quadrupole coupling constants (NQCC, Xij) [U 2], we showed that double zeta (DZ) ab initio molecular orbital calculations using a Huzinaga/Dunning 9s5p/4s basis [3] gave good linear correlations between the experimental microwave (MW) NQCC and the cal­ culated electric field gradients (EFG, <?,,) for a range of heterocyclic and other organic molecules. Fun...