Renormalisation of quark bilinears with Nf=2 Wilson fermions and tree-level improved gauge action

We present results for the renormalisation constants of bilinear quark operators, using the Nf=2 twisted mass Wilson action at maximal twist (which guarantees automatic O(a) improvement) and the tree-level Symanzik improved gauge action. The scale-independent renormalisation constants are computed with a new method, which makes use of both standard twisted mass and Osterwalder-Seiler fermions. Moreover, the results from an RI-MOM calculation are presented for both scale independent and scale dependent renormalisation constants.Comment: 7 pages, talk at The XXV International Symposium on Lattice Field Theory, July 30 - August 4 2007, Regensbur

The Pion Light-Cone Wave Function Phi_pi on the lattice: a partonic signal?

We determine the conditions required to study the pion light-cone wave function Phi_pi with a new method: a direct display of the partons constituting the pion. We present the preliminary results of a lattice computation of Phi_pi following this direction. An auxiliary scalar-quark is introduced. The spectroscopy of its bound states is studied. We observe some indications of a partonic behavior of the system of this scalar-quark and the anti-quark.Comment: 3 pages, 4 figures, Lattice2001(matrixelement

B-physics from lattice QCD...with a twist

We present a precise lattice QCD determination of the b-quark mass, of the B and Bs decay constants and first results for the B-meson bag parameters. For our computation we employ the so-called ratio method and our results benefit from the use of improved interpolating operators for the B-mesons. QCD calculations are performed with Nf = 2 dynamical light-quarks at four values of the lattice spacing and the results are extrapolated to the continuum limit. The preliminary results are mb(mb) = 4.35(12) GeV for the MSbar b-quark mass, fBs = 234(6) MeV and fB = 197(10) MeV for the B-meson decay constants, BBs(mb) = 0.90(5) and BB(mb) = 0.87(5) for the B-meson bag parameters.Comment: 6 pages, 3 figures. Proceedings of the 36th International Conference on High Energy Physics - ICHEP 2012; July 4-11 2012; Melbourne, Australi