Bonn 2010 – scientific programme

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T: Fachverband Teilchenphysik

T 26: Gittereichtheorie II

T 26.7: Talk

Tuesday, March 16, 2010, 18:15–18:30, HG XIII

The form factors of the nucleon in a finite simulation volume — •Ludwig Greil, Thomas R. Hemmert, and Andreas Schäfer — Institut für Theoretische Physik, Universität Regensburg

Lattice QCD simulations for the form factors of the nucleon have now reached the regime of light quark masses. Surprisingly, the observed trend of the lattice data does not uniformly point towards the known values at the physical point (see e.g. ref.[1]). However, within the framework of baryon chiral perturbation theory (ChPT) the non-linear quark-mass dependence in these observables near the physical point is believed to be well understood [2].

It is our hypothesis that corrections from the finite simulation volume, which have not been taken into account systematically e.g. in the analysis of ref.[1], may be responsible for the observed behaviour of the lattice data. In this talk we present first results of an ongoing finite volume study [3] for the form factors of the nucleon. The goal is to calculate the finite volume corrections to next-to-leading one-loop order in ChPT for the case of 2 light quark flavors. In particular, we present new results for the quark-mass dependence of the magnetic moments of the nucleon as a function of the box length L.
This work has been supported by BMBF and DFG.

References:
[1] e.g. S.N. Syritsyn et al., preprint no. [arXiv, 0907.4194].
[2] e.g. M. Göckeler et al., Phys. Rev. D71, 034508 (2005).
[3] L. Greil, T.R. Hemmert and A. Schäfer, in preparation.