We present analytical results concerning lattice calculations of the moments of the twist-two matrix elements. First, we discuss the determination of higher-moments of the deep-inelastic hadron structure functions. By using a fictitious heavy quark, direct calculations of the Compton scattering tensor can be performed in Euclidean space that allow the extraction of the moments of structure functions. This overcomes issues of operator mixing and renormalisation that have so far prohibited lattice computations of higher moments. This approach is especially suitable for the study of the twist-two contributions to isovector quark distributions, which is practical with current computing resources. This method is equally applicable to other quark distributions and to generalised parton distributions. By looking at matrix elements such as (π±| T[Vμ(x)AV(0)]|0) (where Vμ and Aν are vector and axial-vector heavy-light currents) within the same formalism, moments of meson distribution amplitudes can also be extracted. Second, we comment on finite-volume effects in the lattice calculation of the twist-two matrix elements.
|Journal||Proceedings of Science|
|State||Published - 1 Jan 2005|
|Event||23rd International Symposium on Lattice Field Theory, LAT 2005 - Dublin, Ireland|
Duration: 25 Jul 2005 → 30 Jul 2005