Simon Dinter

Nucleon form factors and moments of generalized parton distributions using

We present results on the axial and the electromagnetic form factors of the nucleon, as well as, on the first moments of the nucleon generalized parton distributions using maximally twisted mass fermions. We analyze two N_f=2+1+1 ensembles having pion masses of 210 MeV and 354 MeV at two values of the lattice spacing. The lattice scale is determined using the nucleon mass computed on a total of 18 N_f=2+1+1 ensembles generated at three values of the lattice spacing,

N_f=2+1+1

a

twisted mass fermions

. The renormalization constants are evaluated non-perturbatively with a perturbative subtraction of

Precision Study of Excited State Effects in Nucleon Matrix Elements

{\cal O}(a^2)

Strangeness of the Nucleon from Lattice QCD

-terms. The moments of the generalized parton distributions are given in the

Sigma terms and strangeness content of the nucleon with N f = 2 + 1 + 1 twisted mass fermions

\bar{\rm MS}

Cautionary remarks on the moduli space metric for multidyon simulations

scheme at a scale of

A stochastic method for computing hadronic matrix elements

\mu=2

Confining dyon gas with finite-volume effects under control

GeV. We compare with recent results obtained using different discretization schemes. The implications on the spin content of the nucleon are also discussed.

DARK MATTER SEARCH AND THE SCALAR QUARK CONTENTS OF THE NUCLEON

Abstract We present a dedicated analysis of the influence of excited states on the calculation of nucleon matrix elements. This calculation is performed at a fixed value of the lattice spacing, volume and pion mass that are typical of contemporary lattice computations. We focus on the nucleon axial charge, g A , for which we use about 7500 measurements, and on the average momentum of the unpolarized isovector parton distribution, 〈 x 〉 u − d , for which we use about 23 , 000 measurements. All computations are done employing N f = 2 + 1 + 1 maximally-twisted-mass Wilson fermions and using non-perturbatively calculated renormalization factors. Excited state effects are shown to be negligible for g A , whereas they lead to an O ( 10 % ) downward shift for 〈 x 〉 u − d .