arXiv subjects
Publications and source records attributed to LHPC.
This work presents the first calculation in lattice QCD of three moments of spin-averaged and spin-polarized generalized parton distributions in the proton. It is shown that the slope of the associated generalized form factors decreases significantly as the moment increases, indicating that the transverse size of the light-cone quark distribution decreases as the momentum fraction of the struck parton increases.
The fomalism is developed to express nucleon matrix elements of the electromagnetic current in terms of form factors consistent with the translational, rotational, and parity symmetries of a cubic lattice. We calculate the number of these form factors and show how appropriate linear combinations approach the continuum limit.
Moments of light cone quark density, helicity, and transversity distributions are calculated in unquenched lattice QCD at $β= 5.5$ and $β= 5.3$ using Wilson fermions on $ 16^3 \times 32 $ lattices. These results are combined with earlier calculations at $β= 5.6$ using SESAM configurations to study the continuum limit.
A system of two static quarks, at fixed distances r, and two light quarks is studied on an anisotropic lattice. Excitations by operators emphasizing quark or gluon degrees of freedom are examined. The maximum entropy method is applied in the spectral analysis. These simulations ultimately aim at learning about mechanisms of hadronic interaction.